[ { "kind": "generic", "name": "Aircrete block (standard)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.15, "thickness_mm": 100, "source": "CIBSE Guide A Table 3.x / BS EN 1745 by density — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Aircrete varies ~0.11–0.24 by grade (CIBSE aerated 0.24 / Thermalite Shield 0.17). Prefer manufacturer λ." }, { "kind": "generic", "name": "Aircrete block (thermal grade)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.11, "thickness_mm": 100, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Thermalite Turbo\" = 0.11 (480 kg/m³)." }, { "kind": "generic", "name": "Aluminium (typical alloy)", "manufacturer": null, "category": "metal", "subtype": null, "lambda": 160, "thickness_mm": 2, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Anhydrite / calcium sulphate flow screed", "manufacturer": null, "category": "screed", "subtype": null, "lambda": 1.8, "thickness_mm": 45, "source": "Manufacturer typical (Gyvlon/ARDEX λ 1.2–2.0, common design value 1.8) — added 2026-08-24", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": false, "placeholder": false, "note": "Product-specific; confirm against the screed supplier datasheet." }, { "kind": "generic", "name": "Bituminous felt / membrane", "manufacturer": null, "category": "membrane", "subtype": null, "lambda": 0.23, "thickness_mm": 4, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Confirm against ISO 10456." }, { "kind": "generic", "name": "Bituminous felt underlay (type 1F)", "manufacturer": null, "category": "membrane", "subtype": null, "lambda": 0.23, "thickness_mm": 3, "source": "BS EN 13707 / BS 8747 type 1F bitumen underlay; λ per ISO 10456 bitumen sheet 0.23. Added 2026-08-05 for the hybrid cold-roof case.", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "High-resistance (HR) sarking felt — the traditional impermeable underlay. Condensation default sd 20 m (BS 5250 Table E.2); set the declared value if known." }, { "kind": "generic", "name": "Breather membrane", "manufacturer": null, "category": "membrane", "subtype": null, "lambda": 0.4, "thickness_mm": 1, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Negligible R at 1mm; confirm if used." }, { "kind": "generic", "name": "Brickwork (inner leaf)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.56, "thickness_mm": 102.5, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Brickwork (outer leaf)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.77, "thickness_mm": 102.5, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Cast concrete (dense)", "manufacturer": null, "category": "concrete", "subtype": null, "lambda": 1.4, "thickness_mm": 150, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Cast Concrete (Dense)\" = 1.40 (2100 kg/m³). Normal cast concrete = 1.13 (2000). Reinforced (1% steel) = 2.30 — see id 11." }, { "kind": "generic", "name": "Cellulose (blown)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.039, "thickness_mm": 150, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific; use declared λ." }, { "kind": "generic", "name": "Cement particle board", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.23, "thickness_mm": 12, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Confirm against ISO 10456 / manufacturer." }, { "kind": "generic", "name": "Cement/sand render (external)", "manufacturer": null, "category": "finish", "subtype": null, "lambda": 0.87, "thickness_mm": 20, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Granolithic render/screed\" = 0.87 (2085 kg/m³). Lightweight/insulating renders are lower (~0.50)." }, { "kind": "generic", "name": "Clay roof tile", "manufacturer": null, "category": "covering", "subtype": null, "lambda": 0.84, "thickness_mm": 15, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Clay Tile\" = 0.84 (1900 kg/m³). (ISO 10456 quotes ~1.0.) Tiles have little effect on U." }, { "kind": "generic", "name": "Concrete block (dense aggregate)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 1.13, "thickness_mm": 100, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Density-dependent: 1.13 ≈ 2000 kg/m³; CIBSE heavyweight block = 1.63 at 2300 kg/m³. Prefer product λ for a specific block." }, { "kind": "generic", "name": "Concrete block (medium dense)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.51, "thickness_mm": 100, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Concrete Block (Medium)\" = 0.51 (1400 kg/m³) — exact match." }, { "kind": "generic", "name": "Concrete roof tile", "manufacturer": null, "category": "covering", "subtype": null, "lambda": 1.1, "thickness_mm": 15, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Concrete Tiles\" = 1.10 — exact match." }, { "kind": "generic", "name": "Engineering brick (class A/B)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 1.17, "thickness_mm": 102.5, "source": "CIBSE Guide A ~2000 kg/m³ fired clay — added 2026-08-24", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Range 1.0–1.2 by density; very high vapour resistance vs common brick." }, { "kind": "generic", "name": "EPS (expanded polystyrene)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.038, "thickness_mm": 100, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "ISO 10456 generic EPS ~0.036–0.040 by grade; confirm." }, { "kind": "generic", "name": "EPS (grey / graphite)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.031, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Grey EPS is product-specific; use declared λ." }, { "kind": "generic", "name": "Fibre cement cladding", "manufacturer": null, "category": "cladding", "subtype": null, "lambda": 0.35, "thickness_mm": 10, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Confirm against ISO 10456 / manufacturer." }, { "kind": "generic", "name": "Glass wool quilt", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.04, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific; use declared λ." }, { "kind": "generic", "name": "Gypsum plaster (dense)", "manufacturer": null, "category": "finish", "subtype": null, "lambda": 0.5, "thickness_mm": 13, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Plaster (Dense)\" = 0.50 (1300 kg/m³). \"Gypsum plastering\" = 0.42." }, { "kind": "generic", "name": "Gypsum plaster (lightweight)", "manufacturer": null, "category": "finish", "subtype": null, "lambda": 0.16, "thickness_mm": 13, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Plaster (Lightweight)\" = 0.16 (600 kg/m³)." }, { "kind": "generic", "name": "Hardwood timber", "manufacturer": null, "category": "timber", "subtype": null, "lambda": 0.18, "thickness_mm": 140, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Lightweight/aircrete screed", "manufacturer": null, "category": "screed", "subtype": null, "lambda": 0.24, "thickness_mm": 65, "source": "CIBSE Guide A Table 3.x / BS EN 1745 by density — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Density-dependent; confirm against CIBSE Guide A." }, { "kind": "generic", "name": "Lime plaster", "manufacturer": null, "category": "finish", "subtype": null, "lambda": 0.7, "thickness_mm": 15, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Density-dependent; confirm against ISO 10456 / CIBSE." }, { "kind": "generic", "name": "Limestone", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 1.4, "thickness_mm": 300, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Mild / galvanised steel", "manufacturer": null, "category": "metal", "subtype": null, "lambda": 50, "thickness_mm": 2, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Steel bridging needs BRE Digest 465 method, not simple fraction." }, { "kind": "generic", "name": "Mineral wool quilt", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.04, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific; use declared λ (0.032–0.044 range)." }, { "kind": "generic", "name": "Mineral wool slab", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.038, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific; use declared λ (Rockwool/Knauf)." }, { "kind": "generic", "name": "Mortar (outer leaf)", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 0.94, "thickness_mm": 10, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Natural slate", "manufacturer": null, "category": "covering", "subtype": null, "lambda": 2, "thickness_mm": 8, "source": "CIBSE Guide A (via IES VE Table 6 reproduction) — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "CIBSE Guide A \"Slate Tiles\" = 2.00 — exact match." }, { "kind": "generic", "name": "OSB (oriented strand board)", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.13, "thickness_mm": 9, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Particleboard / fibreboard", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.14, "thickness_mm": 18, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Phenolic board (generic)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.02, "thickness_mm": 90, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Replace with product declared λ (Kingspan Kooltherm etc.)." }, { "kind": "generic", "name": "PIR board (generic)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.022, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Replace with product declared λ (Celotex/Kingspan/Recticel etc.)." }, { "kind": "generic", "name": "Plaster dabs", "manufacturer": null, "category": "finish", "subtype": null, "lambda": 0.43, "thickness_mm": 10, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Plasterboard (high density, ≤900 kg/m³)", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.25, "thickness_mm": 12.5, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Plasterboard (standard, ≤700 kg/m³)", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.21, "thickness_mm": 12.5, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Plywood", "manufacturer": null, "category": "board", "subtype": null, "lambda": 0.13, "thickness_mm": 12, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Polythene VCL / vapour barrier", "manufacturer": null, "category": "membrane", "subtype": null, "lambda": 0.33, "thickness_mm": 0.25, "source": "BS 5250:2011 Table E.2 — 500-gauge polythene, vapour resistance 250 MN·s/g (sd 50 m); negligible thermal R. Added 2026-07-07 for the ISO 13788 check.", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": null }, { "kind": "generic", "name": "Prefabricated timber frame panel", "manufacturer": null, "category": "timber", "subtype": null, "lambda": 0.12, "thickness_mm": 89, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Reconstituted (artificial) stone", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 1.3, "thickness_mm": 100, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Reinforced concrete (1% steel)", "manufacturer": null, "category": "concrete", "subtype": null, "lambda": 2.3, "thickness_mm": 150, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Sand/cement screed (1800 kg/m³)", "manufacturer": null, "category": "screed", "subtype": null, "lambda": 1.15, "thickness_mm": 65, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Sandstone / granite", "manufacturer": null, "category": "masonry", "subtype": null, "lambda": 2.3, "thickness_mm": 300, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Sheep wool", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.039, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific; use declared λ." }, { "kind": "generic", "name": "Softwood timber (joists/frame)", "manufacturer": null, "category": "timber", "subtype": null, "lambda": 0.13, "thickness_mm": 140, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Stainless steel", "manufacturer": null, "category": "metal", "subtype": null, "lambda": 17, "thickness_mm": 2, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Timber cladding (softwood)", "manufacturer": null, "category": "cladding", "subtype": null, "lambda": 0.13, "thickness_mm": 20, "source": "BR 443 (2019) §3 — verified 2026-07-06", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": null }, { "kind": "generic", "name": "Wood fibre board", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.04, "thickness_mm": 100, "source": "Generic placeholder — BR 443 §3 requires manufacturer declared λ (Tier-2 product data)", "sourceUrl": null, "retrieved": null, "sourceType": "convention", "confirmed": false, "weak": false, "paywalled": false, "placeholder": true, "note": "Product-specific (Steico/Pavatex); use declared λ." }, { "kind": "generic", "name": "XPS (extruded polystyrene)", "manufacturer": null, "category": "insulation", "subtype": null, "lambda": 0.034, "thickness_mm": 100, "source": "BS EN ISO 10456:2007 Table 3 — CONFIRM against source copy", "sourceUrl": null, "retrieved": null, "sourceType": "generic", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "ISO 10456 Annex A reviewed XPS; confirm. Product λ preferred." }, { "kind": "product", "name": "A. Proctor Roofshield breather", "manufacturer": "A. Proctor Group", "category": "membrane", "subtype": "breather_membrane", "lambda": 0.33, "thickness_mm": 0.7, "source": "https://www.proctorgroup.com", "sourceUrl": "https://www.proctorgroup.com", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Air/vapour-permeable membrane; negligible R | Rob 2026-07-08: assume 0.33." }, { "kind": "product", "name": "Actis Hybris (multifoil panel)", "manufacturer": "Actis", "category": "insulation", "subtype": "multifoil", "lambda": 0.033, "thickness_mm": 105, "source": "https://www.insulation-actis.com", "sourceUrl": "https://www.insulation-actis.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Honeycomb reflective panel; declared λ_D 0.033 (EN 16012) — model by λ/thickness" }, { "kind": "product", "name": "Adobe / earth block (generic)", "manufacturer": "Generic", "category": "masonry", "subtype": "rammed_earth", "lambda": 0.53, "thickness_mm": 150, "source": "https://www.sciencedirect.com", "sourceUrl": "https://www.sciencedirect.com", "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": false, "placeholder": false, "note": "Unfired earth block; literature 0.52-0.55" }, { "kind": "product", "name": "Amorim Expanded Corkboard (ICB)", "manufacturer": "Amorim", "category": "insulation", "subtype": "cork", "lambda": 0.04, "thickness_mm": 50, "source": "https://www.amorimcorkinsulation.com", "sourceUrl": "https://www.amorimcorkinsulation.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Expanded (black) cork board; declared μ typically 5–14 — explicit μ20 set 2026-08-24 per Amorim TDS (MU20); generic natural-fibre rule μ2 understated it" }, { "kind": "product", "name": "Amvic ICF grey EPS form (per face)", "manufacturer": "Amvic", "category": "insulation", "subtype": "EPS", "lambda": 0.031, "thickness_mm": 75, "source": "https://amvicicf.com/?jet_download=acd6fe31a971da55e71edb7b4a68e4838ab4e0ca", "sourceUrl": "https://amvicicf.com/?jet_download=acd6fe31a971da55e71edb7b4a68e4838ab4e0ca", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Amvic product data sheet '370mm Amvic ICF': grey bead (Neopor or equivalent) EPS, thermal conductivity '0.031W/mK', density min 24 kg/m³; 370 mm block = 85 + 200 core + 85 (U 0.172). Amvic product page: standard block 75 mm each side, λ 0.031, cores 150 (housing) or 200 mm. ONE FACE ONLY — model the concrete core separately." }, { "kind": "product", "name": "Amvic ICF white EPS form (per face)", "manufacturer": "Amvic", "category": "insulation", "subtype": "EPS", "lambda": 0.034, "thickness_mm": 100, "source": "https://amvicicf.com/?jet_download=ef7a839dbaa4385dcdb5d7a87288470bc6dfeaea", "sourceUrl": "https://amvicicf.com/?jet_download=ef7a839dbaa4385dcdb5d7a87288470bc6dfeaea", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Amvic (UK/Ireland) product data sheet '350mm Amvic ICF - White EPS': white bead EPS, thermal conductivity '0.034W/mK' (IS EN 12667), density min 24 kg/m³. 350 mm block = 100 EPS + 150 concrete core + 100 EPS (datasheet U 0.161). ONE FACE ONLY: add the concrete core (150 or 200 mm) as its own layer and the other face as a second EPS layer." }, { "kind": "product", "name": "Ballytherm BTCW Cavity Board (now Unilin)", "manufacturer": "Unilin Insulation (formerly Ballytherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/", "sourceUrl": "https://unilininsulation.co.uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "PARTIAL-FILL rebated foil-faced PIR cavity board. Ballytherm is now Unilin Insulation — check the current CavityTherm/XT datasheet for new work" }, { "kind": "product", "name": "BASF Styrodur 3000 CS", "manufacturer": "BASF", "category": "insulation", "subtype": "XPS", "lambda": 0.033, "thickness_mm": 80, "source": "https://www.styrodur.com", "sourceUrl": "https://www.styrodur.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "λ0.033 constant 30-240mm" }, { "kind": "product", "name": "BASF Walltite (CV 100) closed-cell spray", "manufacturer": "BASF", "category": "insulation", "subtype": "spray_foam", "lambda": 0.025, "thickness_mm": 75, "source": "https://www.master-builders-solutions.com/en-gb (Walltite CV 100 declaration)", "sourceUrl": "https://www.master-builders-solutions.com/en-gb (Walltite CV 100 declaration)", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA-certified closed-cell sprayed PU, λD 0.025 (walltite.basf.co.uk, checked 2026-08-24). UK site now markets plain WALLTITE / WALLTITE One — CV 100 grade name ageing; confirm grade on the BBA cert when specifying." }, { "kind": "product", "name": "Bauder Thermofol U 15 FR (PVC, 1.5 mm)", "manufacturer": "Bauder", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.17, "thickness_mm": 1.5, "source": "https://www.bauder.co.uk/getcontentasset/7c405ca5-a375-477b-a6a0-af97e6d9541f/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauderthermofol-u-15-fr-pvc-roofing-membrane-anthracite-technical-data-sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/getcontentasset/7c405ca5-a375-477b-a6a0-af97e6d9541f/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauderthermofol-u-15-fr-pvc-roofing-membrane-anthracite-technical-data-sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Polyester-reinforced PVC-P single ply, mechanically fixed. TDS 24/03/2026: effective thickness 1.5 mm; mass 1.8 kg/m²; water vapour transmission EN 1931 µ 20,000 (±30 %), sd 30 m; Euroclass E. No declared λ — modelled at the ISO 10456 generic PVC value 0.17 W/mK." }, { "kind": "product", "name": "Bauder Thermoplan T 15 (FPO/TPO, 1.5 mm)", "manufacturer": "Bauder", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.22, "thickness_mm": 1.5, "source": "https://www.bauder.co.uk/getContentAsset/07938b95-4996-41ad-bd03-30a33b158334/7d6e2dfa-e012-4c99-925b-dc695a20fab7/BauderTHERMOPLAN-T-15-FPO-Roofing-Membrane-Silver-Grey-2-wide-rolls-Technical-Data-Sheet-2.pdf", "sourceUrl": "https://www.bauder.co.uk/getContentAsset/07938b95-4996-41ad-bd03-30a33b158334/7d6e2dfa-e012-4c99-925b-dc695a20fab7/BauderTHERMOPLAN-T-15-FPO-Roofing-Membrane-Silver-Grey-2-wide-rolls-Technical-Data-Sheet-2.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Polyester-reinforced flexible polyolefin (FPO/TPO) single ply. TDS 24/03/2026: thickness 1.5 mm; mass 1.8 kg/m²; µ 200,000 (±30 %), sd 300 m; Euroclass E. No declared λ — modelled at the ISO 10456 generic polypropylene value 0.22 W/mK." }, { "kind": "product", "name": "Bauder XPS 300 Inverted", "manufacturer": "Bauder", "category": "insulation", "subtype": "XPS", "lambda": 0.035, "thickness_mm": 120, "source": "https://www.bauder.co.uk/getcontentasset/612240d4-5f8f-48bd-9f93-49844579867b/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauder-xps-300-inverted-insulation-technical-data-sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/getcontentasset/612240d4-5f8f-48bd-9f93-49844579867b/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauder-xps-300-inverted-insulation-technical-data-sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Unfaced XPS for inverted (protected membrane) roofs, 300 kPa. TDS gives 'Declared 0.033 W/mK' and 'Design 0.035 W/mK' – the DESIGN value (0.035) is stored; no thickness bands. Use with the app's Inverted roof option (ΔUr). Water vapour resistivity ≥400 MNs/gm (BS EN 12086)." }, { "kind": "product", "name": "Bauder XPS 500 Inverted (>60mm)", "manufacturer": "Bauder", "category": "insulation", "subtype": "XPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.bauder.co.uk/assets/media/BauderMedia/Products/Insulation/Inverted/XPS-500/Bauder-XPS-500-Inverted-Insulation-Technical-Data-Sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/assets/media/BauderMedia/Products/Insulation/Inverted/XPS-500/Bauder-XPS-500-Inverted-Insulation-Technical-Data-Sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Unfaced XPS, 500 kPa, inverted roofs. TDS: declared '0.036 (>60mm)', design '0.038 (>60mm)' W/mK – design value stored. Water vapour resistivity ≥400 MNs/gm." }, { "kind": "product", "name": "Bauder XPS 500 Inverted (40–60mm)", "manufacturer": "Bauder", "category": "insulation", "subtype": "XPS", "lambda": 0.036, "thickness_mm": 50, "source": "https://www.bauder.co.uk/assets/media/BauderMedia/Products/Insulation/Inverted/XPS-500/Bauder-XPS-500-Inverted-Insulation-Technical-Data-Sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/assets/media/BauderMedia/Products/Insulation/Inverted/XPS-500/Bauder-XPS-500-Inverted-Insulation-Technical-Data-Sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Unfaced XPS, 500 kPa, inverted roofs (paving/decking/ballast/green roof). TDS: declared '0.034 (40-60mm)', design '0.036 (40-60mm)' W/mK – design value stored. Stock 50 mm in this band. Water vapour resistivity ≥400 MNs/gm." }, { "kind": "product", "name": "BauderPIR FA", "manufacturer": "Bauder", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 120, "source": "https://www.bauder.co.uk/getcontentasset/170a6153-1a03-41a2-83d7-98a752bcbbb4/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauderpir-fa-flatboard-insulation-technical-data-sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/getcontentasset/170a6153-1a03-41a2-83d7-98a752bcbbb4/7d6e2dfa-e012-4c99-925b-dc695a20fab7/bauderpir-fa-flatboard-insulation-technical-data-sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aluminium foil facing both sides; warm flat roof flatboard. TDS: declared λD 0.022 W/mK for all thicknesses, no bands. 60-200 mm stock, 40/50/220/240 special order. μ not stated." }, { "kind": "product", "name": "BauderPIR FA-TE", "manufacturer": "Bauder", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 120, "source": "https://www.bauder.co.uk/getContentAsset/9d952312-9dbf-48ce-9051-08c20306d5fc/7d6e2dfa-e012-4c99-925b-dc695a20fab7/BauderPIR-FA-TE-Flatboard-Insulation-Technical-Data-Sheet.pdf", "sourceUrl": "https://www.bauder.co.uk/getContentAsset/9d952312-9dbf-48ce-9051-08c20306d5fc/7d6e2dfa-e012-4c99-925b-dc695a20fab7/BauderPIR-FA-TE-Flatboard-Insulation-Technical-Data-Sheet.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aluminium foil facing top and bottom; warm flat roof flatboard for Bauder single-ply/bituminous systems. TDS: 'Thermal conductivity (λD) EN 13165 W/mK 0.022' – single value, no thickness bands. 30-200 mm stock, 20/180/220/240 special order (min 1,000 m²). μ not stated." }, { "kind": "product", "name": "Baumit NHL Thermo", "manufacturer": "Baumit", "category": "finish", "subtype": "insulating_lime", "lambda": 0.075, "thickness_mm": 40, "source": "https://www.baumit.co.uk", "sourceUrl": "https://www.baumit.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NHL + lightweight aggregate insulating render" }, { "kind": "product", "name": "Beco Wallform EPS form (per leaf)", "manufacturer": "Beco Products", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 55, "source": "https://becowallform.co.uk/wp-content/uploads/BAW-20-139-S-A-UK-2025-03-20-2-CD.pdf", "sourceUrl": "https://becowallform.co.uk/wp-content/uploads/BAW-20-139-S-A-UK-2025-03-20-2-CD.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "KIWA BDA Agrément BAW-20-139-S-A-UK: EPS elements to BS EN 13163, 'declared λD value 0.038 W/mK', density 28 kg/m³, compressive strength 150 kN/m². Wallform 313: inner leaf 55 mm, concrete core 140 mm, outer leaf 117.5 mm (U 0.18); other systems 250 (U 0.30), 375 (0.14), 438 (0.11); core 140–265 mm. ONE LEAF ONLY — add the concrete core and the other leaf as separate layers." }, { "kind": "product", "name": "Besblock Star Performer (cellular)", "manufacturer": "Holcim (Besblock)", "category": "masonry", "subtype": "dense_block", "lambda": 0.649, "thickness_mm": 100, "source": "https://www.holcim.co.uk/sites/uk/files/docs/hol_bp_tds_mar-2026_star_performer_2.pdf", "sourceUrl": "https://www.holcim.co.uk/sites/uk/files/docs/hol_bp_tds_mar-2026_star_performer_2.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "TDS Mar 2026: block type 'Cellular' (24% voids); Thermal conductivity (W/mK) Internal '0.649', External '-'; 'Based on tabulated values from BS EN 1745'. Concrete net dry density 1960 kg/m³; mean unit strength 3.6–10.4 N/mm². Face 440 × 215, thickness 100." }, { "kind": "product", "name": "BEWI (Jablite) EWI EPS 70E (white)", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://bewi.com/products/external-wall-insulation?lang=en-gb", "sourceUrl": "https://bewi.com/products/external-wall-insulation?lang=en-gb", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BEWI UK External Wall Insulation EPS page: standard grade '70 E, 0.038 W/mK', 1200 × 600, 20–200 mm. (HP+ 70E 0.030 grey is already in the library.)" }, { "kind": "product", "name": "BEWI (Jablite) EWI EPS HP 70E (grey)", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://bewi.com/products/external-wall-insulation?lang=en-gb", "sourceUrl": "https://bewi.com/products/external-wall-insulation?lang=en-gb", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BEWI UK External Wall Insulation EPS page: 'HP 70E, 0.032 W/mK', 1200 × 600, 20–200 mm. Graphite EPS (the HP+ grade is 0.030)." }, { "kind": "product", "name": "Bitumen-impregnated fibreboard sheathing", "manufacturer": "Generic", "category": "board", "subtype": "wood_fibre", "lambda": 0.05, "thickness_mm": 25, "source": "Bitumen-impregnated softboard (Isoplaat/Bitroc-type) declarations ~0.048–0.052", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Racking/sarking sheathing on timber frame; vapour-open (μ≈3–5), adds real R unlike OSB." }, { "kind": "product", "name": "Black Mountain NatuHemp", "manufacturer": "Black Mountain", "category": "insulation", "subtype": "hemp", "lambda": 0.039, "thickness_mm": 100, "source": "https://www.blackmountaininsulation.com/products/natuhemp", "sourceUrl": "https://www.blackmountaininsulation.com/products/natuhemp", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Natural hemp fibre batt" }, { "kind": "product", "name": "Brass", "manufacturer": "BS EN ISO 10456:2007 Table 3", "category": "metal", "subtype": "metal", "lambda": 120, "thickness_mm": 2, "source": "BS EN ISO 10456:2007 Table 3", "sourceUrl": null, "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Design value 120 W/mK" }, { "kind": "product", "name": "British Gypsum Gyproc WallBoard", "manufacturer": "British Gypsum", "category": "board", "subtype": "plasterboard", "lambda": 0.19, "thickness_mm": 12.5, "source": "https://www.british-gypsum.com", "sourceUrl": "https://www.british-gypsum.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Standard plasterboard lining (mfr value 0.19)" }, { "kind": "product", "name": "Carpet + underlay", "manufacturer": "Generic", "category": "covering", "subtype": "floor_finish", "lambda": 0.06, "thickness_mm": 10, "source": "CIBSE Guide A — carpet/underlay design value", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": true, "placeholder": false, "note": "Adds ~R 0.17 at 10mm. Usually EXCLUDED from a compliance U-value (removable finish) — include only for in-use heat-loss estimates." }, { "kind": "product", "name": "Cast iron", "manufacturer": "BS EN ISO 10456:2007 Table 3", "category": "metal", "subtype": "metal", "lambda": 50, "thickness_mm": 5, "source": "BS EN ISO 10456:2007 Table 3", "sourceUrl": null, "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Design value 50 W/mK" }, { "kind": "product", "name": "Celcon Coursing Brick (Standard)", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.15, "thickness_mm": 65, "source": "https://www.hplush.com/en-uk/aircrete/products/standard-grade-blocks", "sourceUrl": "https://www.hplush.com/en-uk/aircrete/products/standard-grade-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Standard grade 3.6N, 600 kg/m3, 0.15 W/mK (H+H product page, 15 Sep 2026). Was 0.11, which is the Solar grade (460 kg/m3) figure; Hi-Strength is 0.19." }, { "kind": "product", "name": "Celcon Foundation Block (High Strength)", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.16, "thickness_mm": 275, "source": "https://www.hhcelcon.co.uk", "sourceUrl": "https://www.hhcelcon.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Trench/foundation aircrete" }, { "kind": "product", "name": "Celotex CG5000", "manufacturer": "Celotex (Soprema Sopratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 75, "source": "https://www.insulationsuperstore.co.uk", "sourceUrl": "https://www.insulationsuperstore.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Premium partial-fill cavity, λ0.021" }, { "kind": "product", "name": "Celotex CW4000 Cavity Board", "manufacturer": "Celotex (Soprema)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://www.soprema.co.uk/products/sopratherm-cw4000", "sourceUrl": "https://www.soprema.co.uk/products/sopratherm-cw4000", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "PARTIAL-FILL cavity PIR, 1200×450 boards. Now sold as Sopratherm CW4000." }, { "kind": "product", "name": "Celotex FR5000", "manufacturer": "Celotex (Soprema Sopratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 100, "source": "https://celotex.co.uk/products/fr5000", "sourceUrl": "https://celotex.co.uk/products/fr5000", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Premium flat-roof PIR, λ0.021" }, { "kind": "product", "name": "Celotex GA4000", "manufacturer": "Celotex (Soprema Sopratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://celotex.co.uk/products/ga4000", "sourceUrl": "https://celotex.co.uk/products/ga4000", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General purpose PIR, λ0.022 (BS EN 13165)" }, { "kind": "product", "name": "Celotex PL4000 Insulated Plasterboard", "manufacturer": "Celotex (Soprema)", "category": "insulated_pb", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 52.5, "source": "https://www.soprema.co.uk/products/sopratherm-pl4000", "sourceUrl": "https://www.soprema.co.uk/products/sopratherm-pl4000", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "PIR core λ0.022 (25–65mm) + 12.5mm tapered-edge plasterboard; foil/kraft interlayer acts as VCL. Now sold as Sopratherm PL4000." }, { "kind": "product", "name": "Celotex TB4000", "manufacturer": "Celotex (Soprema Sopratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 25, "source": "https://celotex.co.uk/products/tb4000", "sourceUrl": "https://celotex.co.uk/products/tb4000", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Thin thermal-bridging board" }, { "kind": "product", "name": "Celotex Thermaclass Cavity Wall 21", "manufacturer": "Celotex (Soprema)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 115, "source": "https://www.soprema.co.uk/products/thermaclass-cavity-wall-21", "sourceUrl": "https://www.soprema.co.uk/products/thermaclass-cavity-wall-21", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "FULL-FILL cavity PIR system (10mm residual), 1190×450 T&G boards, λ0.021." }, { "kind": "product", "name": "Celotex XR4000", "manufacturer": "Celotex (Soprema Sopratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://celotex.co.uk/products/xr4000", "sourceUrl": "https://celotex.co.uk/products/xr4000", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General/between-rafter PIR" }, { "kind": "product", "name": "Ceramic / porcelain floor tiles", "manufacturer": "Generic", "category": "covering", "subtype": "floor_finish", "lambda": 1.3, "thickness_mm": 10, "source": "BS EN ISO 10456 Table 3 — ceramics/porcelain 1.3", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Negligible R; relevant to UFH surface build-ups." }, { "kind": "product", "name": "ClayTec Clay Dry Board D25", "manufacturer": "ClayTec", "category": "finish", "subtype": "clay_board", "lambda": 0.13, "thickness_mm": 22, "source": "https://claytec.de/en/", "sourceUrl": "https://claytec.de/en/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Unfired clay dry-lining board" }, { "kind": "product", "name": "ClayTec Clay Insulation Plaster", "manufacturer": "ClayTec", "category": "finish", "subtype": "clay_plaster", "lambda": 0.19, "thickness_mm": 40, "source": "https://claytec.de/en/", "sourceUrl": "https://claytec.de/en/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Lightweight unfired clay insulation plaster" }, { "kind": "product", "name": "ClayTec Clay Plaster Mineral 20", "manufacturer": "ClayTec", "category": "finish", "subtype": "clay_plaster", "lambda": 1.1, "thickness_mm": 20, "source": "https://claytec.de/en/", "sourceUrl": "https://claytec.de/en/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dense clay plaster (thermal mass finish)" }, { "kind": "product", "name": "ClayTec Clayboard Heavy D22", "manufacturer": "ClayTec", "category": "finish", "subtype": "clay_board", "lambda": 0.353, "thickness_mm": 22, "source": "https://claytec.de/en/", "sourceUrl": "https://claytec.de/en/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Heavy unfired clay building board" }, { "kind": "product", "name": "Cob (generic)", "manufacturer": "Generic", "category": "masonry", "subtype": "rammed_earth", "lambda": 0.6, "thickness_mm": 450, "source": "https://link.springer.com/article/10.1557/s43580-023-00630-1", "sourceUrl": "https://link.springer.com/article/10.1557/s43580-023-00630-1", "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": false, "placeholder": false, "note": "Earth-straw; literature 0.61-0.65 | Rob 2026-07-08: 0.6." }, { "kind": "product", "name": "Copper", "manufacturer": "BS EN ISO 10456:2007 Table 3", "category": "metal", "subtype": "metal", "lambda": 380, "thickness_mm": 2, "source": "BS EN ISO 10456:2007 Table 3", "sourceUrl": null, "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Design value 380 W/mK" }, { "kind": "product", "name": "Diathonite Evolution", "manufacturer": "Diasen", "category": "finish", "subtype": "insulating_lime", "lambda": 0.045, "thickness_mm": 40, "source": "https://www.diasen.com/en/diathonite-evolution/", "sourceUrl": "https://www.diasen.com/en/diathonite-evolution/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cork/clay/NHL 3.5 insulating plaster" }, { "kind": "product", "name": "DuPont Tyvek breather membrane", "manufacturer": "DuPont", "category": "membrane", "subtype": "breather_membrane", "lambda": 0.33, "thickness_mm": 0.5, "source": "https://source.thenbs.com/product/tyvek-reflex", "sourceUrl": "https://source.thenbs.com/product/tyvek-reflex", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Negligible thermal resistance | Rob 2026-07-08: assume lambda 0.33 (negligible R)." }, { "kind": "product", "name": "DuPont Tyvek Supro breather", "manufacturer": "DuPont", "category": "membrane", "subtype": "breather_membrane", "lambda": 0.33, "thickness_mm": 0.5, "source": "https://www.dupont.co.uk/products/tyvek-supro.html", "sourceUrl": "https://www.dupont.co.uk/products/tyvek-supro.html", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Negligible thermal resistance | Rob 2026-07-08: assume 0.33." }, { "kind": "product", "name": "Durox Supabloc 3.6N", "manufacturer": "Tarmac (Durox)", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/durox-supabloc", "sourceUrl": "https://www.tarmac.com/products/blocks/durox-supabloc", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N aircrete; higher grades rise to ~0.19" }, { "kind": "product", "name": "Durox Supabloc 7N", "manufacturer": "Tarmac (Durox)", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.19, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/durox-supabloc", "sourceUrl": "https://www.tarmac.com/products/blocks/durox-supabloc", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "High-strength aircrete" }, { "kind": "product", "name": "EcoCocon Straw Panel", "manufacturer": "EcoCocon", "category": "insulation", "subtype": "straw", "lambda": 0.06, "thickness_mm": 400, "source": "https://ecococon.eu/", "sourceUrl": "https://ecococon.eu/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Prefab straw/timber panel; 0.0645 incl. timber" }, { "kind": "product", "name": "EcoTherm Eco-Cavity (partial-fill)", "manufacturer": "EcoTherm", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://www.ecotherm.co.uk", "sourceUrl": "https://www.ecotherm.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "PARTIAL-FILL cavity PIR (a full-fill variant also exists)" }, { "kind": "product", "name": "EcoTherm Eco-Cavity Full Fill", "manufacturer": "EcoTherm", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 115, "source": "https://www.ecotherm.co.uk/gb/en/products/wall-systems/eco-cavity-full-fill", "sourceUrl": "https://www.ecotherm.co.uk/gb/en/products/wall-systems/eco-cavity-full-fill", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill masonry cavity board, aluminium composite foil both sides, 10 mm residual cavity. Product page: thermal conductivity '0.022 W/mK'. Thicknesses 90/115/140 from the EcoTherm datasheet; λ constant across thicknesses. Water vapour resistance >100 MNs/g." }, { "kind": "product", "name": "EcoTherm Eco-Liner Insulated Plasterboard", "manufacturer": "EcoTherm", "category": "insulated_pb", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 62.5, "source": "https://www.insulationshop.co/image/catalog/pdf/EcoTherm_EcoLiner_Data_Sheet.pdf", "sourceUrl": "https://www.insulationshop.co/image/catalog/pdf/EcoTherm_EcoLiner_Data_Sheet.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "PIR core λ0.022 (25–100mm) + 12.5mm plasterboard with integral VCL. Walls, pitched/cold flat roof ceilings, room-in-roof." }, { "kind": "product", "name": "EcoTherm Eco-Versal", "manufacturer": "EcoTherm", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.ecotherm.co.uk/gb/en/products/", "sourceUrl": "https://www.ecotherm.co.uk/gb/en/products/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General purpose PIR" }, { "kind": "product", "name": "Elevate RubberGard EPDM (ex-Firestone, 1.5 mm)", "manufacturer": "Elevate (Holcim)", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.25, "thickness_mm": 1.5, "source": "https://www.permaroof.co.uk/wp-content/uploads/2022/11/Elevate-RubberGard-BBA-2022-rg-cer-gen-bba-en.pdf", "sourceUrl": "https://www.permaroof.co.uk/wp-content/uploads/2022/11/Elevate-RubberGard-BBA-2022-rg-cer-gen-bba-en.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 89/2216 (holder Firestone Building Products EMEA, now Elevate): EPDM membrane 1.1 and 1.5 mm; mass 1.35–2.03 kg/m². The certificate states no vapour resistance or λ — modelled at the ISO 10456 generic rubber (EPDM) value 0.25 W/mK. Certificate PDF is the distributor-hosted copy (permaroof.co.uk)." }, { "kind": "product", "name": "EnergyStore Spacebead", "manufacturer": "EnergyStore", "category": "insulation", "subtype": "blown_bead", "lambda": 0.029, "thickness_mm": 100, "source": "https://www.energystoreltd.com/spacebead", "sourceUrl": "https://www.energystoreltd.com/spacebead", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aerogel-enhanced blown EPS bead" }, { "kind": "product", "name": "EnergyStore Superbead", "manufacturer": "EnergyStore", "category": "insulation", "subtype": "blown_bead", "lambda": 0.033, "thickness_mm": 100, "source": "https://www.energystoreltd.com/superbead/", "sourceUrl": "https://www.energystoreltd.com/superbead/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown EPS bead + adhesive full-fill cavity" }, { "kind": "product", "name": "Engineered timber / wood flooring", "manufacturer": "Generic", "category": "covering", "subtype": "floor_finish", "lambda": 0.14, "thickness_mm": 15, "source": "BS EN ISO 10456 wood-based panels ~0.13–0.18 by density", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Floating or fixed timber floor finish." }, { "kind": "product", "name": "EPDM / single-ply roofing membrane", "manufacturer": "Generic", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.25, "thickness_mm": 1.5, "source": "Synthetic rubber λ 0.25 (ISO 10456); manufacturer EN 1931 declarations μ ~45,000 → sd ≈50 m @1.2mm", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": true, "placeholder": false, "note": "Flat-roof waterproofing (EPDM/TPO/PVC). Vapour-TIGHT (sd 50 m, per declared EN 1931 values) — critical to the warm-roof condensation profile." }, { "kind": "product", "name": "Excel Warmcel (blown cellulose)", "manufacturer": "Excel / CIUR", "category": "insulation", "subtype": "cellulose", "lambda": 0.038, "thickness_mm": 150, "source": "https://www.warmcel.co.uk", "sourceUrl": "https://www.warmcel.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown recycled-newspaper cellulose. Value aligned with generic Warmcel entry 2026-07-07. | Rob 2026-07-08: 0.038." }, { "kind": "product", "name": "Exfoliated vermiculite (loose fill)", "manufacturer": "Generic / Ausperl", "category": "insulation", "subtype": "vermiculite", "lambda": 0.062, "thickness_mm": 100, "source": "https://www.ausperl.com/", "sourceUrl": "https://www.ausperl.com/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Loose fill exfoliated vermiculite" }, { "kind": "product", "name": "Expanded perlite (loose fill)", "manufacturer": "Generic / Silvaperl", "category": "insulation", "subtype": "perlite", "lambda": 0.05, "thickness_mm": 100, "source": "https://www.perlite.org/wp-content/uploads/2018/03/perlite-loosefill-insulation.pdf", "sourceUrl": "https://www.perlite.org/wp-content/uploads/2018/03/perlite-loosefill-insulation.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Loose fill; density 80-110 kg/m³" }, { "kind": "product", "name": "Fermacell Gypsum Fibreboard", "manufacturer": "Fermacell (James Hardie)", "category": "board", "subtype": "plasterboard", "lambda": 0.32, "thickness_mm": 12.5, "source": "https://www.fermacell.co.uk", "sourceUrl": "https://www.fermacell.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Gypsum fibreboard, ~1150 kg/m³" }, { "kind": "product", "name": "Fibre cement slate", "manufacturer": "Generic", "category": "covering", "subtype": "tile", "lambda": 0.45, "thickness_mm": 4, "source": "Fibre cement ~1900 kg/m³, λ 0.35–0.60 by density — negligible effect on U", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Thin covering above a ventilated batten space is normally disregarded anyway (ISO 6946 §6.9.4)." }, { "kind": "product", "name": "FOAMGLAS F", "manufacturer": "Owens Corning", "category": "insulation", "subtype": "foam_glass", "lambda": 0.05, "thickness_mm": 100, "source": "https://www.foamglas.com/en-gb/products/fgbfslabs", "sourceUrl": "https://www.foamglas.com/en-gb/products/fgbfslabs", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "High-load floor/roof; W+F similar" }, { "kind": "product", "name": "FOAMGLAS Perinsul HL", "manufacturer": "Owens Corning", "category": "insulation", "subtype": "foam_glass", "lambda": 0.068, "thickness_mm": 100, "source": "https://www.foamglas.com/en-gb/products/fgbhlperinsul", "sourceUrl": "https://www.foamglas.com/en-gb/products/fgbhlperinsul", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Load-bearing thermal-break block. CORRECTED 2026-07-07: manufacturer declares ≤0.068 (stored 0.058 was wrong, as the old verify_note suspected). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "FOAMGLAS S3", "manufacturer": "Owens Corning", "category": "insulation", "subtype": "foam_glass", "lambda": 0.045, "thickness_mm": 100, "source": "https://www.foamglas.com/en/products/fgbs3slabs", "sourceUrl": "https://www.foamglas.com/en/products/fgbs3slabs", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Higher compressive strength" }, { "kind": "product", "name": "FOAMGLAS T3+", "manufacturer": "Owens Corning", "category": "insulation", "subtype": "foam_glass", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.foamglas.com/en-gb/products/fgbt3slabs", "sourceUrl": "https://www.foamglas.com/en-gb/products/fgbt3slabs", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cellular glass slab" }, { "kind": "product", "name": "FOAMGLAS T4+", "manufacturer": "Owens Corning", "category": "insulation", "subtype": "foam_glass", "lambda": 0.041, "thickness_mm": 100, "source": "https://www.foamglas.com/en-gb/products/fgbt4slabs", "sourceUrl": "https://www.foamglas.com/en-gb/products/fgbt4slabs", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cellular glass slab" }, { "kind": "product", "name": "Forterra Butterley Blue Smooth (perforated Class B engineering)", "manufacturer": "Forterra (Butterley)", "category": "masonry", "subtype": "engineering_brick", "lambda": 1.19, "thickness_mm": 102.5, "source": "https://www.forterra.co.uk/product/blue-smooth-brick/", "sourceUrl": "https://www.forterra.co.uk/product/blue-smooth-brick/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "'λ10,dry 0.72 W/m.K', 'Exposed @ 5% 1.19 W/m.K' (stored = 5% exposed). Vertically perforated 15–25% voids, 75 N/mm², WA 7%, dry weight 2.5 kg, F2 S2 T2." }, { "kind": "product", "name": "Forterra Butterley Class B solid engineering brick", "manufacturer": "Forterra (Butterley)", "category": "masonry", "subtype": "engineering_brick", "lambda": 1.19, "thickness_mm": 102.5, "source": "https://www.forterra.co.uk/product/class-b-solid-engineering-65mm/", "sourceUrl": "https://www.forterra.co.uk/product/class-b-solid-engineering-65mm/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "'Thermal Conductivity (λ10,dry) 0.72'; 'Exposed @ 5% 1.19' W/mK (stored = 5% exposed). Solid, Class B, 75 N/mm², WA 7%, dry weight 3.3 kg, F2, 215 × 102.5 × 65." }, { "kind": "product", "name": "Forterra Butterley wirecut facing brick (e.g. Woodside Mixture)", "manufacturer": "Forterra (Butterley)", "category": "masonry", "subtype": "brick", "lambda": 1.19, "thickness_mm": 102.5, "source": "https://www.forterra.co.uk/product/woodside-mixture-brick/", "sourceUrl": "https://www.forterra.co.uk/product/woodside-mixture-brick/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "'Thermal Conductivity (λ10,dry): 0.72'; 'Thermal Conductivity - Exposed @ 5% (W/m.K): 1.19' (stored = 5% exposed). Wirecut-extruded dense facing, vertically perforated 15–25% voids, 75 N/mm², WA 7%, dry weight 2.5 kg. Forterra publish the same figures across the Butterley wirecut range – check the page for your brick. Note this is well above the generic 0.77 outer-leaf brickwork figure." }, { "kind": "product", "name": "Forterra Jetfloor EPS infill block (grey)", "manufacturer": "Forterra (Bison Precast)", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 150, "source": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "sourceUrl": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 88/2059 PS3 Table 2: Jetfloor EPS infill blocks (wide and narrow) 150 mm, grey grade thermal conductivity 0.030 W/mK (Forterra thermal performance datasheet: 'Jetfloor infill insulation block (0.030 W/m K)'). Sits BETWEEN 150 mm prestressed beams (beam λ 2.00 per datasheet) — use ⋯ → Bridge with the beam fraction; the value covers the EPS block only." }, { "kind": "product", "name": "Forterra Jetfloor EPS infill block (white)", "manufacturer": "Forterra (Bison Precast)", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 150, "source": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "sourceUrl": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 88/2059 PS3 Table 2: white grade EPS infill blocks 150 mm, thermal conductivity 0.038 W/mK. Between 150 mm prestressed beams — bridge with the beam fraction; value covers the block only." }, { "kind": "product", "name": "Forterra Jetfloor EPS top sheet (grey)", "manufacturer": "Forterra (Bison Precast)", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 80, "source": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "sourceUrl": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 88/2059 PS3 Table 2: Jetfloor top sheets 80 mm, grey grade λ 0.030 W/mK. Continuous (unbridged) layer laid over beams and infill blocks under the 70 mm structural concrete topping." }, { "kind": "product", "name": "Forterra Jetfloor EPS top sheet (white)", "manufacturer": "Forterra (Bison Precast)", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 80, "source": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "sourceUrl": "https://forterra.cdn.cloud-infra.co.uk/media/2021/02/24145005/BBA_Jetfloor_Certificate_PS3.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 88/2059 PS3 Table 2: white grade top sheets 80 mm, λ 0.038 W/mK. Continuous layer over beams and blocks under the 70 mm concrete topping." }, { "kind": "product", "name": "Forterra London Brick (LBC) Fletton facing brick", "manufacturer": "Forterra (London Brick)", "category": "masonry", "subtype": "brick", "lambda": 0.75, "thickness_mm": 102.5, "source": "https://www.forterra.co.uk/product/windsor-london-brick/", "sourceUrl": "https://www.forterra.co.uk/product/windsor-london-brick/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Windsor London Brick page: 'Thermal Conductivity (λ10,dry) 0.45' and 'Thermal Conductivity - Exposed @ 5% (W/m.K) 0.75'. Stored λ = the Exposed @ 5% design value (outer leaf); use 0.45 λ10,dry only where a dry inner condition is justified. Pressed Fletton, frogged 15–20% voids, 25 N/mm², water absorption 23%, 215 × 102.5 × 65. Same values on the Commons 65 mm page." }, { "kind": "product", "name": "Forterra London Brick Commons 65mm", "manufacturer": "Forterra (London Brick)", "category": "masonry", "subtype": "brick", "lambda": 0.75, "thickness_mm": 102.5, "source": "https://www.forterra.co.uk/product/commons-65mm/", "sourceUrl": "https://www.forterra.co.uk/product/commons-65mm/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "'λ10,dry 0.45 W/m.K', 'Exposed @ 5% 0.75 W/m.K' (stored = 5% exposed). Common (non-facing) Fletton, frogged 14–20% voids, 25 N/mm², WA 23%, dry weight 1.95 kg." }, { "kind": "product", "name": "GEOCELL Foam Glass Gravel", "manufacturer": "GEOCELL", "category": "insulation", "subtype": "foam_glass_gravel", "lambda": 0.08, "thickness_mm": 200, "source": "https://www.geocell-schaumglas.eu/en/products/foam_glass_gravel/properties/", "sourceUrl": "https://www.geocell-schaumglas.eu/en/products/foam_glass_gravel/properties/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Loose foam-glass aggregate, compacted" }, { "kind": "product", "name": "Glasroc X Sheathing Board", "manufacturer": "British Gypsum (Saint-Gobain)", "category": "board", "subtype": "sheathing_board", "lambda": 0.255, "thickness_mm": 12.5, "source": "https://www.british-gypsum.com", "sourceUrl": "https://www.british-gypsum.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Glass-reinforced gypsum external sheathing" }, { "kind": "product", "name": "Gutex Multitherm", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.04, "thickness_mm": 100, "source": "https://www.gutex.co.uk", "sourceUrl": "https://www.gutex.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "External T&G board, ~140 kg/m³" }, { "kind": "product", "name": "Gutex Thermoflex", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermoflex_TDB_de.pdf", "sourceUrl": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermoflex_TDB_de.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flexible wood-fibre batt between rafters/studs; Gutex TDS (German): 'Nennwert Wärmeleitfähigkeit λD 0,036 W/mK' (German design value λB 0,038), Nennrohdichte ~50 kg/m³, μ 2, cp 2100 J/kgK. Vapour-open. Stored value is the declared λD (the UK design basis)." }, { "kind": "product", "name": "Gutex Thermoroom", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.04, "thickness_mm": 60, "source": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermoroom_TDB_de.pdf", "sourceUrl": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermoroom_TDB_de.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Internal wall insulation board (capillary-active, plasterable); TDS lists two variants: 'Nennwert λD 0,040 / 0,039', 'Nennrohdichte ~150 / ~130', μ 3, cp 2100 J/kgK. The HIGHER λ (0.040, ~150 kg/m³) is stored as the conservative value because the TDS extract did not map thickness to variant – enter 0.039 as a custom λ if your board's DoP says so." }, { "kind": "product", "name": "Gutex Thermosafe", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.gutex.co.uk", "sourceUrl": "https://www.gutex.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rigid board, ~160 kg/m³" }, { "kind": "product", "name": "Gutex Thermowall", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.04, "thickness_mm": 100, "source": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermowall_TDB_de.pdf", "sourceUrl": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Thermowall_TDB_de.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "External wall render-carrying (ETICS) wood-fibre board; TDS: 'Nennwert Wärmeleitfähigkeit λD 0,040 W/mK' (λB 0,042), Nennrohdichte ~160 kg/m³, μ 4, cp 2100 J/kgK. T&G 80–160 mm; square-edge 20–100 mm." }, { "kind": "product", "name": "Gutex Ultratherm", "manufacturer": "Gutex", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.042, "thickness_mm": 100, "source": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Ultratherm_TDB_de.pdf", "sourceUrl": "https://www.gutex.de/Downloads/PDF/Technisches%20Datenblatt/Gutex_Ultratherm_TDB_de.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Sarking / over-rafter roof board, weather-resistant T&G; TDS: 'Nennwert Wärmeleitfähigkeit λD 0,042 W/mK' (λB 0,044), Nennrohdichte ~180 kg/m³, μ 3, cp 2100 J/kgK." }, { "kind": "product", "name": "Gyproc FireLine", "manufacturer": "British Gypsum", "category": "board", "subtype": "plasterboard", "lambda": 0.24, "thickness_mm": 12.5, "source": "https://www.british-gypsum.com", "sourceUrl": "https://www.british-gypsum.com", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Fire-resistant plasterboard" }, { "kind": "product", "name": "Gyproc SoundBloc", "manufacturer": "British Gypsum", "category": "board", "subtype": "plasterboard", "lambda": 0.25, "thickness_mm": 12.5, "source": "https://www.british-gypsum.com", "sourceUrl": "https://www.british-gypsum.com", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "High-density acoustic board" }, { "kind": "product", "name": "Gyproc ThermaLine Basic (EPS)", "manufacturer": "British Gypsum", "category": "insulated_pb", "subtype": "EPS", "lambda": 0.04, "thickness_mm": 22, "source": "https://www.insulationshop.co/british_gypsum_gyproc_thermaline_basic_insulated_plasterboard_22mm.html", "sourceUrl": "https://www.insulationshop.co/british_gypsum_gyproc_thermaline_basic_insulated_plasterboard_22mm.html", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Light thermal upgrade: EPS core λ0.040 (BG PDS — corrected 2026-08-24 from 0.038) + 9.5mm WallBoard; sizes 22/30/40mm. NO integral VCL (EPS is vapour-open) — check the condensation panel and add a VCL if required." }, { "kind": "product", "name": "Gyproc ThermaLine PIR", "manufacturer": "British Gypsum", "category": "insulated_pb", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 53, "source": "https://www.british-gypsum.com/technical-support/self-help-tools/faqs/what-thermal-conductivity-gyproc-thermaline-laminates", "sourceUrl": "https://www.british-gypsum.com/technical-support/self-help-tools/faqs/what-thermal-conductivity-gyproc-thermaline-laminates", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "PIR core λ0.022 + 12.5mm Gyproc WallBoard (λ0.19). Double vapour barrier ~4000 MN·s/g per face; service limit ≤70% RH. MR variant available." }, { "kind": "product", "name": "Gyproc ThermaLine Super (phenolic)", "manufacturer": "British Gypsum", "category": "insulated_pb", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 60, "source": "https://www.insulationshop.co/image/catalog/pdf/British_Gypsum/Gyproc-ThermaLine-SUPER.pdf", "sourceUrl": "https://www.insulationshop.co/image/catalog/pdf/British_Gypsum/Gyproc-ThermaLine-SUPER.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Phenolic core λ0.020–0.021 + plasterboard face, integral VCL ≥100 MN·s/g. Substantial refurb upgrade / room-in-roof." }, { "kind": "product", "name": "Gyvlon Thermio MAX FD E2C anhydrite flow screed", "manufacturer": "Anhydritec (Gyvlon)", "category": "screed", "subtype": "screed", "lambda": 2.5, "thickness_mm": 40, "source": "https://www.gyvlon.co.uk/uploads/Page/20250411_thermio-max-fd-e2c_uk_web.pdf", "sourceUrl": "https://www.gyvlon.co.uk/uploads/Page/20250411_thermio-max-fd-e2c_uk_web.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Fast-drying anhydrite screed. Brochure: 'Thermal conductivity (nominal value) λ=2,5 W/m.K'; dry density 2000 kg/m³; C30 F8; min bonded 20 mm residential / 25 commercial, floating 30 / 35; 15 mm above pipes floating, 10 mm bonded." }, { "kind": "product", "name": "Gyvlon Thermio+ anhydrite flow screed", "manufacturer": "Anhydritec (Gyvlon)", "category": "screed", "subtype": "screed", "lambda": 2.5, "thickness_mm": 50, "source": "https://www.gyvlon.co.uk/uploads/Document/20240611_thermio+_uk_web1.pdf", "sourceUrl": "https://www.gyvlon.co.uk/uploads/Document/20240611_thermio+_uk_web1.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Calcium sulphate (anhydrite) flowing screed for underfloor heating. Brochure: 'Thermal conductivity (nominal value) λ=2,5 W/m.K'; wet density 2200, dry 2000 kg/m³; C30 F8 (BS EN 13813); min unbonded 30 mm, floating residential 35 / commercial 40 mm, nominal 20 mm above UFH pipes. BBA 16/5301." }, { "kind": "product", "name": "H+H Celcon High Strength Grade", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.18, "thickness_mm": 100, "source": "https://www.hhcelcon.co.uk/products-applications/products/high-strength-grade-blocks", "sourceUrl": "https://www.hhcelcon.co.uk/products-applications/products/high-strength-grade-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "7.3N, ~730 kg/m³" }, { "kind": "product", "name": "H+H Celcon Plus (Solar)", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.hhcelcon.co.uk/products-applications/products/plus-blocks", "sourceUrl": "https://www.hhcelcon.co.uk/products-applications/products/plus-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "630mm Plus format, Solar material" }, { "kind": "product", "name": "H+H Celcon Solar Grade", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.hhcelcon.co.uk/products-applications/products/solar-grade-blocks", "sourceUrl": "https://www.hhcelcon.co.uk/products-applications/products/solar-grade-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Lowest-λ aircrete, ~400 kg/m³" }, { "kind": "product", "name": "H+H Celcon Standard Grade", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.15, "thickness_mm": 100, "source": "https://www.hhcelcon.co.uk/products-applications/products/standard-grade-blocks", "sourceUrl": "https://www.hhcelcon.co.uk/products-applications/products/standard-grade-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N, ~600 kg/m³; density-dependent" }, { "kind": "product", "name": "H+H Celcon Super Strength Grade", "manufacturer": "H+H", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.18, "thickness_mm": 100, "source": "https://www.hhcelcon.co.uk", "sourceUrl": "https://www.hhcelcon.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "8.7N, ~730 kg/m³" }, { "kind": "product", "name": "Hempcrete (cast, walling)", "manufacturer": "Generic (natural)", "category": "masonry", "subtype": "hemp", "lambda": 0.07, "thickness_mm": 300, "source": "Typical cast hemp-lime declarations 0.06–0.08 at 275–330 kg/m³", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Cast/sprayed hemp-lime around a timber frame; hygroscopic and vapour-open (μ≈5)." }, { "kind": "product", "name": "Hemsec SIP core PUR (≥120mm)", "manufacturer": "Hemsec", "category": "insulation", "subtype": "PIR", "lambda": 0.028, "thickness_mm": 128, "source": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "sourceUrl": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Hemsec SIPs data sheet: PUR core λ 0.028 W/mK for cores of 120 mm and over; density 42 kg/m³. Panels 150 = 128 core (11 mm OSB) / 120 (15 mm); 175 = 153 / 145; 200 = 178 / 170. ADD the OSB facings separately." }, { "kind": "product", "name": "Hemsec SIP core PUR (70–80mm)", "manufacturer": "Hemsec", "category": "insulation", "subtype": "PIR", "lambda": 0.03, "thickness_mm": 78, "source": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "sourceUrl": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Hemsec SIPs Ltd product data sheet (Hemsec-authored, hosted by partner SIP Build UK; hemsec.com blocked fetching): closed-cell polyurethane core, density 42 kg/m³, core λ 0.030 W/mK for 70–80 mm cores. 100 mm panel = 78 core + 11 mm OSB facings or 70 core + 15 mm OSB. ADD the OSB facings as separate layers." }, { "kind": "product", "name": "Hemsec SIP core PUR (81–119mm)", "manufacturer": "Hemsec", "category": "insulation", "subtype": "PIR", "lambda": 0.029, "thickness_mm": 103, "source": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "sourceUrl": "https://sipbuilduk.co.uk/wp-content/uploads/2023/09/SIPs-data-sheet-final-2022.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Hemsec SIPs data sheet: PUR core λ 0.029 W/mK for cores over 80 and under 120 mm; density 42 kg/m³. 125 mm panel = 103 core (11 mm OSB) or 95 core (15 mm OSB). ADD the OSB facings separately." }, { "kind": "product", "name": "Holcim Masterdenz (solid / hollow)", "manufacturer": "Holcim (Aggregate Industries)", "category": "masonry", "subtype": "dense_block", "lambda": 1.08, "thickness_mm": 100, "source": "https://www.holcim.co.uk/sites/uk/files/docs/052026-hol_bp_tds_masterdenz_2.pdf", "sourceUrl": "https://www.holcim.co.uk/sites/uk/files/docs/052026-hol_bp_tds_masterdenz_2.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "TDS May 2026: Thermal conductivity (W/mK) 'Internal 1.08 / External 1.15' for all solid widths and hollow 140/215; 'Based on tabulated values from BS EN 1745'. Internal (3%) stored. Net dry density 1960 kg/m³. Solid 7.3–22.5 N/mm², hollow 3.6–10.4 N/mm². Formerly Aggregate Industries Masterdenz/Masterblock dense." }, { "kind": "product", "name": "Holcim Masterdenz Cellular", "manufacturer": "Holcim (Aggregate Industries)", "category": "masonry", "subtype": "dense_block", "lambda": 0.649, "thickness_mm": 100, "source": "https://www.holcim.co.uk/sites/uk/files/docs/052026-hol_bp_tds_masterdenz_2.pdf", "sourceUrl": "https://www.holcim.co.uk/sites/uk/files/docs/052026-hol_bp_tds_masterdenz_2.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cellular (voided) dense block rows in the Masterdenz TDS: 'Internal 0.649' W/mK (3% moisture; no external value given) – a whole-unit value including the voids. Concrete net dry density 1960 kg/m³ (unit density lower). Strength 7.3–10.4 N/mm²." }, { "kind": "product", "name": "Holcim Masterdenz Eco", "manufacturer": "Holcim (Aggregate Industries)", "category": "masonry", "subtype": "dense_block", "lambda": 1.08, "thickness_mm": 100, "source": "https://www.holcim.co.uk/sites/uk/files/docs/hol_bp_tds_may-2026_masterdenz-eco_2_final.pdf", "sourceUrl": "https://www.holcim.co.uk/sites/uk/files/docs/hol_bp_tds_may-2026_masterdenz-eco_2_final.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Solid 100 and 140 only. Thermal conductivity (W/mK) Internal 1.08 (3%, stored), External 1.15 (5%), 'Based on tabulated values from BS EN 1745'. Net dry density 1960 kg/m³, mean unit strength 7.3 N/mm². Min 20% non-primary material, 30% lower embodied CO2." }, { "kind": "product", "name": "Holcim Masterlite Pro", "manufacturer": "Holcim (Aggregate Industries)", "category": "masonry", "subtype": "medium_block", "lambda": 0.57, "thickness_mm": 100, "source": "https://www.holcim.co.uk/products/building-products/lightweight-aggregate-blocks/masterlite-pro", "sourceUrl": "https://www.holcim.co.uk/products/building-products/lightweight-aggregate-blocks/masterlite-pro", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Thermal conductivity (W/mK) Internal 0.57 (3% moisture, stored), External 0.61 (5% moisture). Density 1450 kg/m³. Strengths 3.6, 7.3, 10.4 N/mm². Solid medium-density block; 300 mm = trenchblock variant. Formerly Aggregate Industries Masterlite. BS EN 771-3." }, { "kind": "product", "name": "Holcim Masterlite Ultra18", "manufacturer": "Holcim (Aggregate Industries)", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.31, "thickness_mm": 100, "source": "https://www.holcim.co.uk/products/building-products/lightweight-aggregate-blocks/masterlite-ultra", "sourceUrl": "https://www.holcim.co.uk/products/building-products/lightweight-aggregate-blocks/masterlite-ultra", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Thermal conductivity (W/mK) 'Internal 0.31, External 0.34' – Internal = 3% moisture (stored), External = 5% moisture. Density 1050 kg/m³. Strengths 3.6 & 7.3 N/mm². Solid lightweight aggregate block, 440 × 215 face. TDS: https://www.holcim.co.uk/sites/uk/files/docs/holcim-masterlite-ultra-tds.pdf" }, { "kind": "product", "name": "Icynene H2Foam Lite (open-cell spray)", "manufacturer": "Icynene (Huntsman)", "category": "insulation", "subtype": "spray_foam", "lambda": 0.039, "thickness_mm": 100, "source": "https://www.huntsmanbuildingsolutions.com/en-GB (H2Foam Lite LDC50 declaration)", "sourceUrl": "https://www.huntsmanbuildingsolutions.com/en-GB (H2Foam Lite LDC50 declaration)", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Open-cell sprayed PU, vapour-open, λD 0.039 (installer TDS; corrected 2026-08-24). Brand now Huntsman Building Solutions; newer certs BBA 20/5846 / KIWA BDA BAR-17-010." }, { "kind": "product", "name": "IKO Armourplan P (PVC, 1.2 mm)", "manufacturer": "IKO Polymeric", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.17, "thickness_mm": 1.2, "source": "https://ikogroup.co.uk/wp-content/uploads/2024/09/Technical-Data-Sheet-TDS-IKO-Armourplan-P.pdf", "sourceUrl": "https://ikogroup.co.uk/wp-content/uploads/2024/09/Technical-Data-Sheet-TDS-IKO-Armourplan-P.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Woven polyester scrim reinforced PVC-P single ply, mechanically fixed. TDS July 2024: thickness 1.2 mm; mass 1700 g/m²; Ext.F.AB (BS EN 476-3). No µ or λ stated — modelled at the ISO 10456 generic PVC value 0.17 W/mK." }, { "kind": "product", "name": "IKO Enertherm ALU", "manufacturer": "IKO", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://ikogroup.co.uk/wp-content/uploads/2025/05/Technical-Data-Sheet-TDS-IKO-enertherm-ALU.pdf", "sourceUrl": "https://ikogroup.co.uk/wp-content/uploads/2025/05/Technical-Data-Sheet-TDS-IKO-enertherm-ALU.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "7-layer gas-tight aluminium facings (μ>100,000) — flat/pitched roofs, floors, frame walls. Effectively vapour-tight." }, { "kind": "product", "name": "IKO enertherm MG (<120mm)", "manufacturer": "IKO", "category": "insulation", "subtype": "PIR", "lambda": 0.026, "thickness_mm": 100, "source": "https://products.enertherm.eu/products/download/24/uk/I", "sourceUrl": "https://products.enertherm.eu/products/download/24/uk/I", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR with perforated coated glass-fabric facing both sides; for bitumen, mastic asphalt, single-ply or adhesive-bonded systems. IKO enertherm datasheet (generated 16 Sep 2026): 'λD: 0,026 W/(m.K) untill 120 mm, 0,025 W/(m.K) from 120 mm'. The eu.iko.com product page still shows older 0.027/0.026 figures – datasheet value used. μ PIR core 60 (glass-fabric facing, not foil-tight)." }, { "kind": "product", "name": "IKO enertherm MG (≥120mm)", "manufacturer": "IKO", "category": "insulation", "subtype": "PIR", "lambda": 0.025, "thickness_mm": 120, "source": "https://products.enertherm.eu/products/download/24/uk/I", "sourceUrl": "https://products.enertherm.eu/products/download/24/uk/I", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR, perforated coated glass-fabric facings. Datasheet: 'λD 0,025 W/(m.K) from 120 mm'. μ PIR core 60." }, { "kind": "product", "name": "IsoHemp Hemp-Lime Block", "manufacturer": "IsoHemp", "category": "masonry", "subtype": "hemp", "lambda": 0.071, "thickness_mm": 150, "source": "https://www.isohemp.com/en/hemp-blocks", "sourceUrl": "https://www.isohemp.com/en/hemp-blocks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Hemp-lime masonry block (0.087 variant exists)" }, { "kind": "product", "name": "Isover Cavity Wall Slab CWS 32", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://isover.co.uk", "sourceUrl": "https://isover.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cavity slab; number = λ×1000" }, { "kind": "product", "name": "Isover Cavity Wall Slab CWS 34", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.034, "thickness_mm": 100, "source": "https://isover.co.uk/products/isover-cavity-wall-slab-cws-34", "sourceUrl": "https://isover.co.uk/products/isover-cavity-wall-slab-cws-34", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cavity slab" }, { "kind": "product", "name": "Isover Cavity Wall Slab CWS 36", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.isover.co.uk", "sourceUrl": "https://www.isover.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cavity slab" }, { "kind": "product", "name": "Isover Metac 034", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.034, "thickness_mm": 100, "source": "https://www.isover.co.uk", "sourceUrl": "https://www.isover.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rafter-level roll" }, { "kind": "product", "name": "Isover Spacesaver", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.044, "thickness_mm": 150, "source": "https://www.isover.co.uk/documents/product-datasheet/isover-pds-isover-spacesaver.pdf", "sourceUrl": "https://www.isover.co.uk/documents/product-datasheet/isover-pds-isover-spacesaver.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Loft/cold-roof roll" }, { "kind": "product", "name": "Isover Timber Frame Batt 32", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 140, "source": "https://www.isover.co.uk/products/timber-frame-batt-32", "sourceUrl": "https://www.isover.co.uk/products/timber-frame-batt-32", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "570×1175mm batts for 600mm stud centres." }, { "kind": "product", "name": "Isover Timber Frame Batt 35", "manufacturer": "Saint-Gobain Isover", "category": "insulation", "subtype": "glass_wool", "lambda": 0.035, "thickness_mm": 140, "source": "https://www.isover.co.uk/products/timber-frame-batt-35", "sourceUrl": "https://www.isover.co.uk/products/timber-frame-batt-35", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Timber-frame wall batt." }, { "kind": "product", "name": "Jablite EWI EPS HP+ 70E (grey)", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://bewi.com/wp-content/uploads/External-Wall-Insulation_datasheet_181022.pdf", "sourceUrl": "https://bewi.com/wp-content/uploads/External-Wall-Insulation_datasheet_181022.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Premium graphite EPS for external wall insulation; white EWI EPS 70E = 0.038." }, { "kind": "product", "name": "Jablite Jabfloor 100", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.jablite.co.uk", "sourceUrl": "https://www.jablite.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "EPS100 floor board" }, { "kind": "product", "name": "Jablite Jabfloor 150", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.035, "thickness_mm": 100, "source": "https://www.jablite.co.uk", "sourceUrl": "https://www.jablite.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "EPS150 floor board" }, { "kind": "product", "name": "Jablite Jabfloor 200", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.034, "thickness_mm": 100, "source": "https://www.jablite.co.uk", "sourceUrl": "https://www.jablite.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "EPS200 floor board" }, { "kind": "product", "name": "Jablite Jabfloor 70", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.jablite.co.uk", "sourceUrl": "https://www.jablite.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "EPS70 floor board" }, { "kind": "product", "name": "Jablite Jabfloor HP Plus 70", "manufacturer": "Jablite (BEWI)", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://www.jablite.co.uk", "sourceUrl": "https://www.jablite.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Graphite (grey) EPS70. CORRECTED 2026-07-07: current HP Plus declares 0.030 (0.032 was a legacy HP figure). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Jackon Jackodur KF 300 Standard", "manufacturer": "Jackon (BEWI)", "category": "insulation", "subtype": "XPS", "lambda": 0.034, "thickness_mm": 100, "source": "https://www.jackon.co.uk", "sourceUrl": "https://www.jackon.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "λ_D 0.034 (EN 13164)" }, { "kind": "product", "name": "K Systems E EWI grey EPS 100 (030)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsE-20-5744-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsE-20-5744-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744 (K Systems E): 'K Systems E, Grey EPS (EPS 100 030)', λD 0.030 W/mK, 1200 × 600, nominal density 15–21 kg/m³, 60–250 mm, BS EN 13163:2012, Euroclass E. The same board is certified for steel frame as K Systems Exicco E (BBA 20/5756)." }, { "kind": "product", "name": "K Systems E EWI grey EPS 70 (032)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsE-20-5744-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsE-20-5744-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744: 'K Systems E, Grey EPS (EPS 70 032)', λD 0.032 W/mK, nominal density 15–21 kg/m³, 60–260 mm, BS EN 13163:2012, Euroclass E." }, { "kind": "product", "name": "K Systems M EWI mineral wool dual density (036)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsM-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsM-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744 (K Systems M): 'K Systems M MW Dual Density 036', λD 0.036 W/mK, nominal densities 160/100 kg/m³ (outer/inner), 100–250 mm. Non-combustible stone wool." }, { "kind": "product", "name": "K Systems M EWI mineral wool slab (036)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsM-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsM-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744: 'K Systems M MW EWI Slab 036', λD 0.036 W/mK, nominal density 105 kg/m³, 100–260 mm. Mono-density stone wool slab." }, { "kind": "product", "name": "K Systems P EWI phenolic (30–44mm)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 40, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsP-20-5744-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsP-20-5744-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744 (K Systems P): 'Phenolic 021: 0.021 W/mK (thicknesses 30-44 mm)', BS EN 13166:2012, nominal density 35 kg/m³, compressive ≥100 kPa, C-s1,d0. Unbranded phenolic board supplied as K Systems P." }, { "kind": "product", "name": "K Systems P EWI phenolic (45–120mm)", "manufacturer": "K Systems (Kilwaughter)", "category": "insulation", "subtype": "phenolic", "lambda": 0.02, "thickness_mm": 90, "source": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsP-20-5744-BBA.pdf", "sourceUrl": "https://s3.eu-west-1.amazonaws.com/k-systems.s3-assets.com/downloads/KSystemsP-20-5744-BBA.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 20/5744: 'Phenolic 020: 0.020 W/mK (45-120 mm)', nominal density 35 kg/m³." }, { "kind": "product", "name": "Kay-Metzeler Kay-Cel EPS70", "manufacturer": "Kay-Metzeler", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 50, "source": "https://insulationgo.co.uk", "sourceUrl": "https://insulationgo.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Standard white EPS70, 15 kg/m³" }, { "kind": "product", "name": "Kevothermal VIP", "manufacturer": "Kevothermal", "category": "insulation", "subtype": "vip", "lambda": 0.007, "thickness_mm": 30, "source": "https://www.kevothermal.com/", "sourceUrl": "https://www.kevothermal.com/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aged 0.007; initial ~0.0036" }, { "kind": "product", "name": "Kingspan GreenGuard GG300", "manufacturer": "Kingspan", "category": "insulation", "subtype": "XPS", "lambda": 0.033, "thickness_mm": 100, "source": "https://www.insulation.kingspan.com/gb/en/products/insulation-boards/roof-insulation-boards/kingspan-greenguard-gg300", "sourceUrl": "https://www.insulation.kingspan.com/gb/en/products/insulation-boards/roof-insulation-boards/kingspan-greenguard-gg300", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "300 kPa XPS. CORRECTED 2026-07-07: re-declared to 0.033 for all 30-180mm (Kingspan DoP GG300.008, Oct 2024). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Kingspan GreenGuard GG500", "manufacturer": "Kingspan", "category": "insulation", "subtype": "XPS", "lambda": 0.034, "thickness_mm": 60, "source": "https://assets.materialsmarket.com/technical-downloads/", "sourceUrl": "https://assets.materialsmarket.com/technical-downloads/", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "500 kPa XPS for heavy-load inverted roofs/podium decks. Banded λ per UK DoP: 0.034 (50–60mm) / 0.036 (>60mm)." }, { "kind": "product", "name": "Kingspan GreenGuard GG700", "manufacturer": "Kingspan", "category": "insulation", "subtype": "XPS", "lambda": 0.035, "thickness_mm": 60, "source": "https://www.kingspan.com/content/dam/kingspan/kil/products/kingspan-greenguard-gb-and-ireland/kingspan-greenguard-heavy-duty-floors-brochure-en-gb-ie.pdf", "sourceUrl": "https://www.kingspan.com/content/dam/kingspan/kil/products/kingspan-greenguard-gb-and-ireland/kingspan-greenguard-heavy-duty-floors-brochure-en-gb-ie.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rigid XPS, 700 kPa compressive strength; inverted roofs / heavy-duty floors. Brochure: '0.035 W/mK (insulant thickness 50, 60 and 80 mm)'. Water vapour resistivity typically >400 MNs/gm." }, { "kind": "product", "name": "Kingspan Kooltherm K103 Floorboard", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Premium floorboard, λ0.019. Glass-tissue faced (NOT foil)" }, { "kind": "product", "name": "Kingspan Kooltherm K106 Cavity", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 90, "source": "https://www.insulation-online.com/product/kingspan-kooltherm-k106/", "sourceUrl": "https://www.insulation-online.com/product/kingspan-kooltherm-k106/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Near-full-fill cavity board. TRIPLE-CHECKED 2026-08-24: current GB brochure (11th issue 07/2026) declares 0.019 — the 0.018 on datasheet mirrors is NOT the current declaration" }, { "kind": "product", "name": "Kingspan Kooltherm K107 Pitched Roof", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://www.insulation-online.com/product/kingspan-kooltherm-k107/", "sourceUrl": "https://www.insulation-online.com/product/kingspan-kooltherm-k107/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Replaces K7. TRIPLE-CHECKED 2026-08-24: current brochure (6th issue 04/2026) declares 0.019, single value 25-150mm" }, { "kind": "product", "name": "Kingspan Kooltherm K108 Cavity", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Partial-fill cavity phenolic. TRIPLE-CHECKED 2026-08-24: current brochure (10th issue 04/2026) declares 0.019" }, { "kind": "product", "name": "Kingspan Kooltherm K110 Soffit", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Soffit board. TRIPLE-CHECKED 2026-08-24: 0.019 confirmed by current brochure (14th issue 01/2026); circulating 0.018 claims unsupported" }, { "kind": "product", "name": "Kingspan Kooltherm K112 Framing", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://assets.materialsmarket.com/technical-downloads/", "sourceUrl": "https://assets.materialsmarket.com/technical-downloads/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Replaces K12. TRIPLE-CHECKED 2026-08-24: current brochure (8th issue 03/2026) declares 0.019, single value" }, { "kind": "product", "name": "Kingspan Kooltherm K118 Insulated Plasterboard", "manufacturer": "Kingspan", "category": "insulated_pb", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 52.5, "source": "https://www.kingspan.com/gb/en/products/insulation/insulation-boards/kooltherm/kooltherm-k118-insulated-plasterboard/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation/insulation-boards/kooltherm/kooltherm-k118-insulated-plasterboard/", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Phenolic core: TRIPLE-CHECKED 2026-08-24 — stored 0.019 (conservative; a materialsmarket datasheet mirror shows 0.018, but every current GB Kooltherm brochure declares 0.019 — confirm against the live K118 datasheet before improving it) + 12.5mm tapered-edge plasterboard; low-e foil back = integral VCL. Auto-adds core + facing as two layers — set the core to (overall − 12.5mm)." }, { "kind": "product", "name": "Kingspan Kooltherm K12 Framing", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "LEGACY product (superseded by K112). Original UK datasheet likely declared 0.020 ≥45mm (same core as K7); 0.021 kept as conservative — confirm against an archived datasheet before sign-off." }, { "kind": "product", "name": "Kingspan Kooltherm K15 Rainscreen", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rainscreen board. Thickness-banded: 0.022 (25-44mm) / 0.021 (>=45mm) — 27th issue 07/2025. Stored 0.021 applies at the 100mm default" }, { "kind": "product", "name": "Kingspan Kooltherm K5 External Wall", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 80, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "λ0.022 for 25-44mm, 0.021 for ≥45mm. Glass-tissue faced (NOT foil) — no low-e cavity benefit" }, { "kind": "product", "name": "Kingspan Kooltherm K7 Pitched Roof", "manufacturer": "Kingspan", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 100, "source": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090329.pdf", "sourceUrl": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090329.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NSAI cert bands: 0.022 (15-24mm), 0.021 (25-44mm), 0.020 (45-120mm), 0.021 (121-159mm). Default 100mm -> 0.020 (corrected 2026-07-07). Superseded by K107. | Rob 2026-07-08: confirmed 0.021." }, { "kind": "product", "name": "Kingspan OPTIM-R (VIP)", "manufacturer": "Kingspan Insulation", "category": "insulation", "subtype": "vip", "lambda": 0.007, "thickness_mm": 30, "source": "https://www.kingspan.com/gb/en/business-groups/kingspan-insulation/optim-r/", "sourceUrl": "https://www.kingspan.com/gb/en/business-groups/kingspan-insulation/optim-r/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aged λ_D 0.007; microporous VIP core" }, { "kind": "product", "name": "Kingspan Styrozone N300R (>60mm)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "XPS", "lambda": 0.035, "thickness_mm": 100, "source": "https://www.insulation.kingspan.com/gb/en/", "sourceUrl": "https://www.insulation.kingspan.com/gb/en/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "UNRESOLVED 2026-07-07: sources conflict and band boundary may be 120mm not 60mm. 0.038 kept as conservative — manual datasheet check required before sign-off. | Rob 2026-07-08: 0.035." }, { "kind": "product", "name": "Kingspan Styrozone N300R (≤60mm)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "XPS", "lambda": 0.035, "thickness_mm": 50, "source": "https://www.insulation.kingspan.com/gb/en/", "sourceUrl": "https://www.insulation.kingspan.com/gb/en/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "UNRESOLVED 2026-07-07: sources conflict (0.029-0.036) and Kingspan page shows no table. 0.036 kept as the conservative figure — manual datasheet check required before sign-off. | Rob 2026-07-08: 0.035." }, { "kind": "product", "name": "Kingspan TEK SIP core (PUR)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.024, "thickness_mm": 112, "source": "https://www.kingspan.com/content/dam/kingspan/kil/products/tek-building-system-gb-and-ireland/kingspan-tek-building-system-specification-manual-en-gb-ie.pdf", "sourceUrl": "https://www.kingspan.com/content/dam/kingspan/kil/products/tek-building-system-gb-and-ireland/kingspan-tek-building-system-specification-manual-en-gb-ie.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Kingspan TEK Building System specification manual (GB/IE): 'The declared thermal conductivity of the insulation core of the TEK Building System panels is 0.024 W/mK'; core 112 or 142 mm rigid urethane (32–35 kg/m³) with up to 15 mm OSB/3 bonded each side. Panel 142 = 15 + 112 + 15; 172 = 15 + 142 + 15 (manufacturer panel R 4.85 / 6.10). ADD the two 15 mm OSB/3 facings as separate layers." }, { "kind": "product", "name": "Kingspan Thermafloor TF70", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Therma range floor PIR" }, { "kind": "product", "name": "Kingspan Thermapitch TP10", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Therma range PIR (TP10/TW55/TF70 same board)" }, { "kind": "product", "name": "Kingspan Thermaroof TR24 (<80mm)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.027, "thickness_mm": 50, "source": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "sourceUrl": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR for partially bonded torch-applied bituminous waterproofing. Brochure (9th issue 12/2025): '0.027 W/mK (insulant thickness < 80mm)'. GB boards made 30–130 mm (range only, individual sizes not listed – thickness left free); 140/150 mm from Ireland. Bitumen-coated glass tissue + PP fleece upper facing, mineralised glass tissue lower. Water vapour resistivity >300 MNs/gm." }, { "kind": "product", "name": "Kingspan Thermaroof TR24 (≥120mm)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.024, "thickness_mm": 120, "source": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "sourceUrl": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR, torch-on bituminous systems. Brochure: '0.024 W/mK (insulant thickness ≥ 120 mm)'. 140/150 mm made in Ireland (1200 × 1200 boards)." }, { "kind": "product", "name": "Kingspan Thermaroof TR24 (80–119mm)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.025, "thickness_mm": 100, "source": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "sourceUrl": "https://www.kingspan.com/content/dam/kingspan/kil/products/thermaroof-tr24-gb-and-ireland/kingspan-thermaroof-tr24-brochure-en-gb.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR, torch-on bituminous systems. Brochure: '0.025 W/mK (insulant thickness 80 - 119 mm)'. Range only – thickness left free within the band." }, { "kind": "product", "name": "Kingspan Thermaroof TR26", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 120, "source": "https://ukflatroofing.com/product/kingspan-tr26-foil-faced-flat-roof-board", "sourceUrl": "https://ukflatroofing.com/product/kingspan-tr26-foil-faced-flat-roof-board", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Flat-roof PIR, low-e foil both sides — mechanically fixed single-ply / green roof." }, { "kind": "product", "name": "Kingspan Thermaroof TR27 (tissue-faced)", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.025, "thickness_mm": 100, "source": "https://ukflatroofing.com/product/kingspan-tr27-tissue-faced-flat-roof-board", "sourceUrl": "https://ukflatroofing.com/product/kingspan-tr27-tissue-faced-flat-roof-board", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "THICKNESS-BANDED λ per current UK DoP (checked 2026-08-24): 0.027 (<80mm) / 0.025 (80–119mm) / 0.024 (≥120mm) — set the band for your thickness. Coated glass-TISSUE faced (bonded/torch-on felt, asphalt): NOT foil-vapour-tight — μ 60 core default applied, not the foil sd 200 m." }, { "kind": "product", "name": "Kingspan Thermawall TW50", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://www.nsai.ie/images/uploads/certification-agrement/IAB030196.pdf", "sourceUrl": "https://www.nsai.ie/images/uploads/certification-agrement/IAB030196.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Partial-fill cavity PIR (NSAI cert)" }, { "kind": "product", "name": "Kingspan Thermawall TW55", "manufacturer": "Kingspan", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.kingspan.com/gb/en/products/insulation-boards/", "sourceUrl": "https://www.kingspan.com/gb/en/products/insulation-boards/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Therma range framing/wall board" }, { "kind": "product", "name": "Klober Permo Air breather", "manufacturer": "Klober", "category": "membrane", "subtype": "breather_membrane", "lambda": 0.33, "thickness_mm": 0.5, "source": "https://klober.co.uk", "sourceUrl": "https://klober.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Air-open vapour-permeable roof membrane; negligible R | Rob 2026-07-08: assume 0.33." }, { "kind": "product", "name": "Knauf Aquapanel Exterior (cement board)", "manufacturer": "Knauf", "category": "board", "subtype": "cement_board", "lambda": 0.35, "thickness_mm": 12.5, "source": "https://media.knauf.com/a/6AsXezumGffSDWGfV27Tta", "sourceUrl": "https://media.knauf.com/a/6AsXezumGffSDWGfV27Tta", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cement board sheathing, 1150 kg/m³, μ 66 (datasheet)." }, { "kind": "product", "name": "Knauf Earthwool DriTherm 32", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity slab; number = λ×1000" }, { "kind": "product", "name": "Knauf Earthwool DriTherm 34", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.034, "thickness_mm": 100, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity slab" }, { "kind": "product", "name": "Knauf Earthwool DriTherm 37", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.037, "thickness_mm": 100, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_dritherm_cavity_slabs_glass-datasheet-en-uk.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity slab" }, { "kind": "product", "name": "Knauf Earthwool FrameTherm Roll 32", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 140, "source": "https://knauf.com/en-GB/p/product/frametherm-r-roll-32", "sourceUrl": "https://knauf.com/en-GB/p/product/frametherm-r-roll-32", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Timber-frame roll (source URL refreshed 2026-07-07 — old PDF link dead)" }, { "kind": "product", "name": "Knauf Earthwool FrameTherm Roll 35", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.035, "thickness_mm": 140, "source": "https://knauf.com/en-GB/p/product/frametherm-r-roll-35", "sourceUrl": "https://knauf.com/en-GB/p/product/frametherm-r-roll-35", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Timber-frame roll (source URL refreshed 2026-07-07 — old PDF link dead)" }, { "kind": "product", "name": "Knauf Earthwool Loft Roll 44", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.044, "thickness_mm": 150, "source": "https://pim.knaufinsulation.com/files/download/kine1508dat_loft_roll_40_and_44-datasheet.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/kine1508dat_loft_roll_40_and_44-datasheet.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Loft/pitched-roof roll" }, { "kind": "product", "name": "Knauf Fireshield", "manufacturer": "Knauf", "category": "board", "subtype": "plasterboard", "lambda": 0.24, "thickness_mm": 12.5, "source": "https://www.knauf.com/en-GB", "sourceUrl": "https://www.knauf.com/en-GB", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Fire-resistant board" }, { "kind": "product", "name": "Knauf FrameTherm Roll 40", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.04, "thickness_mm": 140, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_frametherm_rolls-datasheet-en-uk.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_frametherm_rolls-datasheet-en-uk.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Economy timber-frame roll (32/35 already listed)." }, { "kind": "product", "name": "Knauf Loft Roll 40", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.04, "thickness_mm": 150, "source": "https://pim.knaufinsulation.com/files/download/kine1508dat_loft_roll_40_and_44-datasheet.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/kine1508dat_loft_roll_40_and_44-datasheet.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Combi-cut loft roll, ceiling level." }, { "kind": "product", "name": "Knauf OmniFit Slab 32", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_omnifit_slab_32_and_35-datasheet.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_omnifit_slab_32_and_35-datasheet.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Multi-application slab: frame walls, rafters, internal walls, floors. (Earthwool name retired ~2023.)" }, { "kind": "product", "name": "Knauf OmniFit Slab 35", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "glass_wool", "lambda": 0.035, "thickness_mm": 100, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_omnifit_slab_32_and_35-datasheet.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_omnifit_slab_32_and_35-datasheet.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Multi-application friction-fit slab." }, { "kind": "product", "name": "Knauf Rocksilk RainScreen Slab", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.034, "thickness_mm": 100, "source": "https://knauf.com/en-GB/", "sourceUrl": "https://knauf.com/en-GB/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA rainscreen sheathing slab, A1" }, { "kind": "product", "name": "Knauf Rocksilk RS45", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.035, "thickness_mm": 50, "source": "https://pim.knaufinsulation.com/files/download/knauf_insulation_rocksilk_building_slab-datasheet-en-uk_feb24.pdf", "sourceUrl": "https://pim.knaufinsulation.com/files/download/knauf_insulation_rocksilk_building_slab-datasheet-en-uk_feb24.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "45 kg/m³ building slab, A1" }, { "kind": "product", "name": "Knauf Soundshield Plus", "manufacturer": "Knauf", "category": "board", "subtype": "plasterboard", "lambda": 0.24, "thickness_mm": 12.5, "source": "https://www.knauf.com/en-GB", "sourceUrl": "https://www.knauf.com/en-GB", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Dense acoustic board" }, { "kind": "product", "name": "Knauf Supafil Cavity Wall 34", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "blown_fibre", "lambda": 0.034, "thickness_mm": 100, "source": "https://www.knaufinsulation.com/blowing-wool", "sourceUrl": "https://www.knaufinsulation.com/blowing-wool", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown glass wool full-fill cavity; ~25 kg/m³ installed" }, { "kind": "product", "name": "Knauf Supafil Frame", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "blown_fibre", "lambda": 0.033, "thickness_mm": 140, "source": "https://www.knaufinsulation.com/blowing-wool", "sourceUrl": "https://www.knaufinsulation.com/blowing-wool", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown glass wool for timber-frame cavities" }, { "kind": "product", "name": "Knauf Supafil Loft", "manufacturer": "Knauf Insulation", "category": "insulation", "subtype": "blown_fibre", "lambda": 0.042, "thickness_mm": 250, "source": "https://www.knaufinsulation.com/blowing-wool", "sourceUrl": "https://www.knaufinsulation.com/blowing-wool", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown glass wool loft/open-blow" }, { "kind": "product", "name": "Knauf Thermal Laminate (EPS)", "manufacturer": "Knauf", "category": "insulated_pb", "subtype": "EPS", "lambda": 0.04, "thickness_mm": 30, "source": "https://www.insulationking.co.uk/products/knauf-drywall-thermal-laminate", "sourceUrl": "https://www.insulationking.co.uk/products/knauf-drywall-thermal-laminate", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "EPS core λ0.040 (conservative — Knauf PDS is silent on λ; merchants claim 0.038, sibling Gyproc Basic declares 0.040; corrected 2026-08-24) + 9.5mm Knauf Wallboard. Vapour-open (no VCL) — check condensation risk." }, { "kind": "product", "name": "Knauf Wallboard", "manufacturer": "Knauf", "category": "board", "subtype": "plasterboard", "lambda": 0.19, "thickness_mm": 12.5, "source": "https://www.knauf.com/en-GB", "sourceUrl": "https://www.knauf.com/en-GB", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Standard plasterboard" }, { "kind": "product", "name": "Knauf XPS Laminate Plus", "manufacturer": "Knauf", "category": "insulated_pb", "subtype": "XPS", "lambda": 0.033, "thickness_mm": 40, "source": "https://media.wickes.co.uk/is/content/wickes/K0020_163698_TECH_0", "sourceUrl": "https://media.wickes.co.uk/is/content/wickes/K0020_163698_TECH_0", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "XPS core λ0.033 + plasterboard. XPS is moderately vapour-resistant but has no foil VCL. Walls, room-in-roof, refurb." }, { "kind": "product", "name": "Kore External EWI EPS70 silver (grey)", "manufacturer": "Kore Insulation", "category": "insulation", "subtype": "EPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "sourceUrl": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "KORE External Wall Insulation Design Guide: 'KORE External EPS70 Silver, thermal conductivity 0.031 W/mK, density 15 kg/m3', 100–300 mm. Graphite (silver) EPS." }, { "kind": "product", "name": "Kore External EWI EPS70 white", "manufacturer": "Kore Insulation", "category": "insulation", "subtype": "EPS", "lambda": 0.037, "thickness_mm": 100, "source": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "sourceUrl": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "KORE External Wall Insulation Design Guide (2018, still hosted): 'KORE External EPS70 White, thermal conductivity 0.037 W/mK, density 15 kg/m3', 100–300 mm." }, { "kind": "product", "name": "Kore External EWI plinth EPS200 white", "manufacturer": "Kore Insulation", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 50, "source": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "sourceUrl": "https://www.kore-system.com/wp-content/uploads/2022/02/KORE_External_Wall_Design_Guide_2018.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "KORE External Wall Insulation Design Guide: 'KORE External Plinth EPS200 White, 0.032 W/mK, density 30 kg/m3', 10–100 mm; high-density board for the plinth below DPC." }, { "kind": "product", "name": "Kore Floor EPS100 Silver", "manufacturer": "Kore Insulation", "category": "insulation", "subtype": "EPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://www.kore-system.com", "sourceUrl": "https://www.kore-system.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Graphite (silver) EPS100" }, { "kind": "product", "name": "Kore Floor EPS70 Silver", "manufacturer": "Kore Insulation", "category": "insulation", "subtype": "EPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://www.kore-system.com", "sourceUrl": "https://www.kore-system.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Graphite (silver) EPS70" }, { "kind": "product", "name": "Lead", "manufacturer": "BS EN ISO 10456:2007 Table 3", "category": "metal", "subtype": "metal", "lambda": 35, "thickness_mm": 2, "source": "BS EN ISO 10456:2007 Table 3", "sourceUrl": null, "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Design value 35 W/mK" }, { "kind": "product", "name": "Lightherm INSU (poured insulation)", "manufacturer": "Lightherm", "category": "insulation", "subtype": "poured_insulation", "lambda": 0.041, "thickness_mm": 100, "source": "https://lightherm.co.uk/", "sourceUrl": "https://lightherm.co.uk/", "retrieved": "2026-09-10", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Cement-bound coated-EPS insulation, mixed on site and poured or pumped to depth rather than supplied as boards. It is the INSULATION layer - model any levelling or structural screed over it as its own separate layer. LAMBDA IS DENSITY-DEPENDENT: 0.041 belongs to the INSU formulation at 130 kg/m3. The denser LW grade (270 kg/m3, sold for load reduction) has no published lambda and will be materially higher; licensee data for the same technology puts a 250 kg/m3 mix nearer 0.067 W/mK. If the mix is not INSU, get the figure from the supplier." }, { "kind": "product", "name": "Lignacite GP (Standard)", "manufacturer": "Lignacite", "category": "masonry", "subtype": "medium_block", "lambda": 0.47, "thickness_mm": 100, "source": "https://lignacite.co.uk", "sourceUrl": "https://lignacite.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Medium-dense ~1450 kg/m³; 0.51 exposed" }, { "kind": "product", "name": "Lignacite Standard Block", "manufacturer": "Lignacite", "category": "masonry", "subtype": "medium_block", "lambda": 0.9, "thickness_mm": 100, "source": "https://lignacite.co.uk/the-thermal-performance-of-concrete-an-introduction/", "sourceUrl": "https://lignacite.co.uk/the-thermal-performance-of-concrete-an-introduction/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "@3% MC: 100mm=0.90; 140mm SP=0.79" }, { "kind": "product", "name": "Lignacrete (Dense)", "manufacturer": "Lignacite", "category": "masonry", "subtype": "dense_block", "lambda": 1.33, "thickness_mm": 100, "source": "https://lignacite.co.uk", "sourceUrl": "https://lignacite.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "High-strength dense block" }, { "kind": "product", "name": "Lime Green Solo Onecoat Lime Plaster", "manufacturer": "Lime Green", "category": "finish", "subtype": "lime_plaster", "lambda": 0.54, "thickness_mm": 12, "source": "https://www.lime-green.co.uk", "sourceUrl": "https://www.lime-green.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Non-insulating finish lime plaster" }, { "kind": "product", "name": "Mannok Aircrete Standard", "manufacturer": "Mannok", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.17, "thickness_mm": 100, "source": "https://www.bpsbuildit.co.uk/mannok-aircrete-440mm-x-100mm-3-6n-mm2-standard-block-10-m2-0-17w-mk--1", "sourceUrl": "https://www.bpsbuildit.co.uk/mannok-aircrete-440mm-x-100mm-3-6n-mm2-standard-block-10-m2-0-17w-mk--1", "retrieved": "2026-08-24", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "3.6N, ~600 kg/m³; foundation sizes available." }, { "kind": "product", "name": "Mannok Aircrete Super", "manufacturer": "Mannok", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.12, "thickness_mm": 100, "source": "https://source.thenbs.com/product/mannok-aircrete-super-blocks/oUZSgL4QqkLFnSR7nEt4TS/sSfF4Dst5YqUZM8EPkzUrU", "sourceUrl": "https://source.thenbs.com/product/mannok-aircrete-super-blocks/oUZSgL4QqkLFnSR7nEt4TS/sSfF4Dst5YqUZM8EPkzUrU", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "2.9N, ~480 kg/m³ (ex-Quinn Lite)." }, { "kind": "product", "name": "Mannok Therm Cavity MC", "manufacturer": "Mannok", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://mannokbuild.com/pir-insulation/mannok-therm-cavity-mc/", "sourceUrl": "https://mannokbuild.com/pir-insulation/mannok-therm-cavity-mc/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Partial-fill cavity PIR" }, { "kind": "product", "name": "Mannok Therm Floor MF", "manufacturer": "Mannok", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://mannokbuild.com/pir-insulation/mannok-therm-floor-mf/", "sourceUrl": "https://mannokbuild.com/pir-insulation/mannok-therm-floor-mf/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Floor PIR (ex-Quinn Therm)" }, { "kind": "product", "name": "Mannok Therm Roof MR", "manufacturer": "Mannok", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://mannok.blob.core.windows.net/mannokbuild/dlm_uploads/DOP_005-20-Mannok-Therm-Roof-MR.pdf", "sourceUrl": "https://mannok.blob.core.windows.net/mannokbuild/dlm_uploads/DOP_005-20-Mannok-Therm-Roof-MR.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "DoP 005/20 (Nov 2020): foil-faced pitched roof board, thermal conductivity '0.022 W/mK' (EN 12667), thickness 20–200 mm (range – thickness left free). Also NSAI Agrément 05/0223 (0.022 W/mK, 20–200 mm, low-e composite foil, vapour resistivity >300 MNs/gm, 2400 × 1200)." }, { "kind": "product", "name": "Mapei Mapetherm EWI EPS 70 (grey, 031)", "manufacturer": "Mapei", "category": "insulation", "subtype": "EPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/mapetherm-eps-ps1-bba.pdf?sfvrsn=6c255e71_11", "sourceUrl": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/mapetherm-eps-ps1-bba.pdf?sfvrsn=6c255e71_11", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 13/4977 PS1: 'Mapetherm EPS 70 031 (grey)', λD 0.031 W/mK, EPS 70, nominal density 15–17 kg/m³, 40–300 mm in 10 mm increments. Graphite EPS." }, { "kind": "product", "name": "Mapei Mapetherm EWI EPS 70 (white, 038)", "manufacturer": "Mapei", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/mapetherm-eps-ps1-bba.pdf?sfvrsn=6c255e71_11", "sourceUrl": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/mapetherm-eps-ps1-bba.pdf?sfvrsn=6c255e71_11", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 13/4977 PS1 (Mapetherm EPS EWI system): 'Mapetherm EPS 70 038 (white)', λD 0.038 W/mK, EPS 70 to BS EN 13163:2012, nominal density 15 kg/m³, 40–300 mm in 10 mm increments, Euroclass E." }, { "kind": "product", "name": "Mapei Mapetherm EWI mineral wool dual density (036)", "manufacturer": "Mapei", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/ps5---mapetherm-mineral-wool-lwsf-bba.pdf?sfvrsn=19b57089_7", "sourceUrl": "https://cdnmedia.mapei.com/docs/librariesprovider12/certifications/ps5---mapetherm-mineral-wool-lwsf-bba.pdf?sfvrsn=19b57089_7", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 13/4977 PS5 (Mapetherm MW on light steel frame): 'Mapetherm MW Dual Density 036', λD 0.036 W/mK, nominal densities 160/100 kg/m³ (outer/inner), 60–150 mm (thinner for reveals)." }, { "kind": "product", "name": "Marmox Multiboard", "manufacturer": "Marmox", "category": "board", "subtype": "thermal_board", "lambda": 0.036, "thickness_mm": 20, "source": "https://www.marmox.co.uk", "sourceUrl": "https://www.marmox.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "XPS-cored waterproof board" }, { "kind": "product", "name": "Marmox Thermoblock", "manufacturer": "Marmox", "category": "board", "subtype": "thermal_board", "lambda": 0.047, "thickness_mm": 65, "source": "https://www.marmox.co.uk", "sourceUrl": "https://www.marmox.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Load-bearing junction block; model as thermal bridge" }, { "kind": "product", "name": "Medium dense aggregate block (ex-Hanson)", "manufacturer": "Generic / former Hanson", "category": "masonry", "subtype": "medium_block", "lambda": 0.47, "thickness_mm": 100, "source": "https://www.heidelbergmaterials.co.uk/en", "sourceUrl": "https://www.heidelbergmaterials.co.uk/en", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Density-dependent. Hanson-branded blocks are no longer sold — treat this as a typical medium-dense aggregate block and confirm the conductivity against the block actually specified" }, { "kind": "product", "name": "MISAPOR Foam Glass Gravel", "manufacturer": "MISAPOR", "category": "insulation", "subtype": "foam_glass_gravel", "lambda": 0.09, "thickness_mm": 200, "source": "https://www.misapor.ch/en/", "sourceUrl": "https://www.misapor.ch/en/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Installed/compacted ~0.08-0.09" }, { "kind": "product", "name": "Pavaflex (Pavatex)", "manufacturer": "Soprema", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.soprema.co.uk/products/pavaflex", "sourceUrl": "https://www.soprema.co.uk/products/pavaflex", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flexible wood-fibre slab; Confort 36 = 0.036" }, { "kind": "product", "name": "Pavatex Isolair Multi (100–200mm)", "manufacturer": "Pavatex (Soprema)", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.041, "thickness_mm": 100, "source": "https://www.soprema.co.uk/products/isolair-multi", "sourceUrl": "https://www.soprema.co.uk/products/isolair-multi", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Sarking/sheathing wood-fibre board; 100–200 mm 'λd 0.041 W/m.K' per Soprema UK page." }, { "kind": "product", "name": "Pavatex Isolair Multi (30–35mm)", "manufacturer": "Pavatex (Soprema)", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.044, "thickness_mm": 35, "source": "https://www.soprema.co.uk/products/isolair-multi", "sourceUrl": "https://www.soprema.co.uk/products/isolair-multi", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Higher-density sarking/sheathing wood-fibre board; λd is thickness-dependent on the Soprema UK page: 30–35 mm 'λd 0.044 W/m.K'. Vapour-open, weather-resistant." }, { "kind": "product", "name": "Pavatex Isolair Multi (40–80mm)", "manufacturer": "Pavatex (Soprema)", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.043, "thickness_mm": 60, "source": "https://www.soprema.co.uk/products/isolair-multi", "sourceUrl": "https://www.soprema.co.uk/products/isolair-multi", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Sarking/sheathing wood-fibre board; 40–80 mm 'λd 0.043 W/m.K' per Soprema UK page." }, { "kind": "product", "name": "Pavatex Pavatherm", "manufacturer": "Pavatex (Soprema)", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.soprema.co.uk/products/pavatherm", "sourceUrl": "https://www.soprema.co.uk/products/pavatherm", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rigid wood-fibre board for roof/wall/floor; Soprema UK product page: 'Thermal conductivity (λd) 0.038 W/m.K', R 1.05 (40 mm) to 5.25 (200 mm). Vapour-open. Density/μ not on the page (TDS host blocked)." }, { "kind": "product", "name": "Pavatex Pavatherm-Profil", "manufacturer": "Pavatex (Soprema)", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.044, "thickness_mm": 40, "source": "https://www.soprema.co.uk/products/pavatherm-profil", "sourceUrl": "https://www.soprema.co.uk/products/pavatherm-profil", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Profiled T&G rigid wood-fibre board (1100 × 580 mm); page: 'λd 0.044 W/m.K', Rd 0.90 m²K/W at 40 mm." }, { "kind": "product", "name": "Plasmor Aglite Ultima", "manufacturer": "Plasmor", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.31, "thickness_mm": 100, "source": "https://www.plasmor.co.uk/building-blocks/ultra-lightweight-blocks/aglite-ultima/", "sourceUrl": "https://www.plasmor.co.uk/building-blocks/ultra-lightweight-blocks/aglite-ultima/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Ultra-lightweight; 10.4N grade = 0.36" }, { "kind": "product", "name": "Plasmor Fibolite", "manufacturer": "Plasmor", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.24, "thickness_mm": 100, "source": "https://www.plasmor.co.uk/media/dp0frbji/02_plasmor_fibolite_w11_22ep.pdf", "sourceUrl": "https://www.plasmor.co.uk/media/dp0frbji/02_plasmor_fibolite_w11_22ep.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N = 0.24; 7.3N = 0.28" }, { "kind": "product", "name": "Plasmor Stranlite", "manufacturer": "Plasmor", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.41, "thickness_mm": 100, "source": "https://www.plasmor.co.uk/building-blocks/lightweight-blocks/stranlite/", "sourceUrl": "https://www.plasmor.co.uk/building-blocks/lightweight-blocks/stranlite/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "4.2N/7.3N = 0.41; 10.4N = 0.43" }, { "kind": "product", "name": "Polarwall XPS ICF form, per face (50mm)", "manufacturer": "Polarwall", "category": "insulation", "subtype": "XPS", "lambda": 0.034, "thickness_mm": 50, "source": "https://www.polarwall.co.uk/wp-content/uploads/2023/02/Polarwall-BBA-14-5127.pdf", "sourceUrl": "https://www.polarwall.co.uk/wp-content/uploads/2023/02/Polarwall-BBA-14-5127.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 14/5127 Table 4 'Typical extruded polystyrene insulation thermal conductivity (λD) values': 50 mm 0.034 W/mK. XPS planking, nominal density 35 kg/m³, compressive strength 300 kN/m². The inner face is always 50 mm (Standard Polarwall = 50 outer / 50 inner). ONE FACE ONLY: add the concrete core (100–300 mm, 150 typical above ground, 200+ basements) as its own layer and the other face as a second XPS layer." }, { "kind": "product", "name": "Polarwall XPS ICF form, per face (75–150mm)", "manufacturer": "Polarwall", "category": "insulation", "subtype": "XPS", "lambda": 0.036, "thickness_mm": 75, "source": "https://www.polarwall.co.uk/wp-content/uploads/2023/02/Polarwall-BBA-14-5127.pdf", "sourceUrl": "https://www.polarwall.co.uk/wp-content/uploads/2023/02/Polarwall-BBA-14-5127.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 14/5127 Table 4 λD: 75 mm 0.036, 100 mm 0.036, 150 mm 0.036 W/mK — the OUTER face of Polarwall Xtra X25 (75), X50 (100), X100 (150); the inner face is 50 mm in every variant (use the 50 mm entry). Nominal density 35 kg/m³. Model the concrete core as a separate layer." }, { "kind": "product", "name": "Polyfoam Floorboard Standard", "manufacturer": "Polyfoam XPS (Ravago)", "category": "insulation", "subtype": "XPS", "lambda": 0.033, "thickness_mm": 100, "source": "https://polyfoamxps.co.uk/products/polyfoam-floorboard-standard/", "sourceUrl": "https://polyfoamxps.co.uk/products/polyfoam-floorboard-standard/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "200 kPa XPS floor board" }, { "kind": "product", "name": "Polythene DPM (1200 gauge, below slab)", "manufacturer": "Generic", "category": "membrane", "subtype": "vcl", "lambda": 0.33, "thickness_mm": 0.3, "source": "BS 5250 Table E.2 — 1000-gauge polythene sd 100 m; 1200g ≈ 120 m", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Damp-proof membrane under ground-bearing slabs; negligible R, very high vapour resistance." }, { "kind": "product", "name": "Porotherm PLS100 clay block", "manufacturer": "Wienerberger", "category": "masonry", "subtype": "porotherm", "lambda": 0.29, "thickness_mm": 100, "source": "https://www.wienerberger.co.uk/products/blocks.html", "sourceUrl": "https://www.wienerberger.co.uk/products/blocks.html", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Fired-clay hollow block; dry λ_D per EN 1745" }, { "kind": "product", "name": "Porotherm PLS140 clay block", "manufacturer": "Wienerberger", "category": "masonry", "subtype": "porotherm", "lambda": 0.26, "thickness_mm": 140, "source": "https://www.wienerberger.co.uk/products/blocks.html", "sourceUrl": "https://www.wienerberger.co.uk/products/blocks.html", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Fired-clay hollow block" }, { "kind": "product", "name": "Porotherm PLS190 clay block", "manufacturer": "Wienerberger", "category": "masonry", "subtype": "porotherm", "lambda": 0.26, "thickness_mm": 190, "source": "https://www.wienerberger.co.uk/products/blocks.html", "sourceUrl": "https://www.wienerberger.co.uk/products/blocks.html", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Fired-clay hollow block" }, { "kind": "product", "name": "Rammed earth (generic)", "manufacturer": "Generic", "category": "masonry", "subtype": "rammed_earth", "lambda": 0.9, "thickness_mm": 400, "source": "https://www.mdpi.com/2075-5309/11/12/635", "sourceUrl": "https://www.mdpi.com/2075-5309/11/12/635", "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": false, "placeholder": false, "note": "Density-dependent; literature 0.52-1.21 | Rob 2026-07-08: 0.9." }, { "kind": "product", "name": "Ravatherm XPS X 300 SB (>120mm)", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.031, "thickness_mm": 150, "source": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-300-sb", "sourceUrl": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-300-sb", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "TDS: λD '0.031 > 120mm W/m.K'; Rd 125 mm 4.00, 150 mm 4.80; CS(10) 300 kPa; μ 150." }, { "kind": "product", "name": "Ravatherm XPS X 300 SB (≤120mm)", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-300-sb", "sourceUrl": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-300-sb", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Successor to Styrofoam Floormate 300-A / Perimate. TDS: λD '0.030 ≤ 120mm W/m.K'; Rd 30 mm 1.00 … 100 mm 3.30; CS(10) 300 kPa (BS EN 826); μ 150. Basements, ground floors, cold stores, swimming pools." }, { "kind": "product", "name": "Ravatherm XPS X 300 SL (>120mm)", "manufacturer": "Ravago", "category": "insulation", "subtype": "XPS", "lambda": 0.031, "thickness_mm": 140, "source": "https://www.ravagobuildingsolutions.com", "sourceUrl": "https://www.ravagobuildingsolutions.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "λ0.031 above 120mm" }, { "kind": "product", "name": "Ravatherm XPS X 300 SL (≤120mm)", "manufacturer": "Ravago", "category": "insulation", "subtype": "XPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://www.ravagobuildingsolutions.com", "sourceUrl": "https://www.ravagobuildingsolutions.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "300 kPa XPS; λ0.030 to 120mm" }, { "kind": "product", "name": "Ravatherm XPS X 500 SL", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://ravagobuildingsolutions.com/uk/wp-content/uploads/sites/30/2025/12/ravatherm-xps-x-500-sl-tds-version-10-20251212.pdf", "sourceUrl": "https://ravagobuildingsolutions.com/uk/wp-content/uploads/sites/30/2025/12/ravatherm-xps-x-500-sl-tds-version-10-20251212.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Successor to DuPont Styrofoam Floormate 500-A (the Styrofoam Europe business is now Ravago). TDS v10 (12/2025): 'Thermal Conductivity Declared (λD) 0.031 W/m.K'; 50–120 mm; Rd 50 mm 1.60, 75 mm 2.40, 100 mm 3.20; CS(10) 500 kPa; shiplap edge; Euroclass E. Inverted roofs, floors, base slabs, car parks, cold stores." }, { "kind": "product", "name": "Ravatherm XPS X 700 SL", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.031, "thickness_mm": 100, "source": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-700-sl", "sourceUrl": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-700-sl", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Successor to Styrofoam Floormate 700-A. TDS: declared λD 0.031 W/m.K; 50–120 mm; Rd 50 mm 1.60, 75 mm 2.40, 100 mm 3.20; CS(10) 700 kPa; typical density 42 kg/m³; μ (min) 150. Load-bearing industrial floors, base slabs, high-load car parks." }, { "kind": "product", "name": "Ravatherm XPS X FUSION 300 SL", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.03, "thickness_mm": 120, "source": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-fusion-300-sl", "sourceUrl": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-fusion-300-sl", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Thick-board XPS for inverted roofs (successor to Roofmate SL-A in thick sizes). TDS: declared λD 0.030 W/m.K (BS EN 13164); 30–200 mm; Rd 50 mm 1.65 … 200 mm 6.65; CS(10) 300 kPa; shiplap; μ (min) 150." }, { "kind": "product", "name": "Ravatherm XPS X ULTRA 300 SL", "manufacturer": "Ravago Building Solutions", "category": "insulation", "subtype": "XPS", "lambda": 0.027, "thickness_mm": 130, "source": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-ultra-300-sl", "sourceUrl": "https://ravagobuildingsolutions.com/uk/en/downloads/tds/ravatherm-xps-x-ultra-300-sl", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Grey (infrared-absorber) XPS, successor to Styrofoam Xenergy. TDS: declared λD 0.027 W/(m·K) for 70–175 mm; Rd 70 mm 2.60 … 175 mm 6.45; CS(10) 300 kPa (90 days); typical density 32 kg/m³; μ 150; Euroclass E. Inverted roofs." }, { "kind": "product", "name": "RCM Cemboard", "manufacturer": "RCM", "category": "board", "subtype": "cement_board", "lambda": 0.26, "thickness_mm": 12, "source": "https://www.rcm.co.uk", "sourceUrl": "https://www.rcm.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Cement-bonded particle board" }, { "kind": "product", "name": "Recticel Eurothane Eurodeck", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 120, "source": "https://www.recticelinsulation.com/sites/default/files/downloads/Eurothane_Eurodeck_en-gb%20(1).pdf", "sourceUrl": "https://www.recticelinsulation.com/sites/default/files/downloads/Eurothane_Eurodeck_en-gb%20(1).pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flat roof PIR with gas-diffusion-tight multilayer facing both sides (mechanically fixed / adhered single-ply and bituminous systems). Datasheet: 'λD 0.022 W/m.K' for all thicknesses, no bands." }, { "kind": "product", "name": "Recticel Eurothane GP", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.recticelinsulation.com/en-gb/eurothane-gp", "sourceUrl": "https://www.recticelinsulation.com/en-gb/eurothane-gp", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General purpose PIR" }, { "kind": "product", "name": "Recticel Eurowall Cavity", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://www.recticelinsulation.com/en-gb/eurowall-cavity", "sourceUrl": "https://www.recticelinsulation.com/en-gb/eurowall-cavity", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Partial-fill cavity PIR" }, { "kind": "product", "name": "Recticel Eurowall+", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://www.recticelinsulation.com/en-gb/eurowall-plus", "sourceUrl": "https://www.recticelinsulation.com/en-gb/eurowall-plus", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity PIR" }, { "kind": "product", "name": "Recticel Instafit", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 50, "source": "https://www.recticelinsulation.com/en-gb/product/instafit", "sourceUrl": "https://www.recticelinsulation.com/en-gb/product/instafit", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General-purpose PIR board for lofts, internal walls, ceilings and floors (NOT a cavity board). Product page: 'λ = 0.022 W/mK'. Straight edges; 1200 × 600, 2400 × 1200, 1200 × 450. 75 mm made to order." }, { "kind": "product", "name": "Recticel Plylok (PIR + 6mm ply deck)", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 110, "source": "https://www.recticelinsulation.com/en-gb/product/plylok", "sourceUrl": "https://www.recticelinsulation.com/en-gb/product/plylok", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Composite warm flat roof deck: PIR bonded to a 6 mm plywood top layer. Core 'λ = 0,022 W/mK'. Page lists 90/110/120 mm with R 4.05/4.95/5.40 m²K/W – these are the PIR thicknesses; ADD the 6 mm plywood as its own layer above it. Compressive strength >140 kPa, Euroclass F." }, { "kind": "product", "name": "Recticel Powerdeck F", "manufacturer": "Recticel", "category": "insulation", "subtype": "PIR", "lambda": 0.025, "thickness_mm": 100, "source": "https://www.recticelinsulation.com/en-gb/product/powerdeck-f", "sourceUrl": "https://www.recticelinsulation.com/en-gb/product/powerdeck-f", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "THICKNESS-DEPENDENT λ (Recticel R-table): ~0.027 @50mm, 0.025 @100mm, 0.024 ≥120mm — check the band for your thickness. Corrected from blanket 0.024 in 2026-07-07 audit. | Rob 2026-07-08 bands: <=79mm 0.027 / 80-119mm 0.025 / >=120mm 0.024." }, { "kind": "product", "name": "Resistant Multi-proXS (MgO board)", "manufacturer": "Resistant Building Products", "category": "board", "subtype": "magnesium_board", "lambda": 0.307, "thickness_mm": 12, "source": "https://www.resistant.co.uk/products/multi-proxs/", "sourceUrl": "https://www.resistant.co.uk/products/multi-proxs/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Named product, replacing a generic MgO entry on 2026-09-06: generic magnesium oxide board has no defensible single λ (formulations run 0.11-0.45 W/mK), which is why the old entry sat UNVERIFIED with a caution. λ 0.307 and density 1050 kg/m³ are both declared on the maker’s own page, and the density is confirmed four ways from their sheet weights (12mm 2400×1200 = 36.3 kg → 1050; 6.5 and 9mm derive to 1051). Thicknesses are the three they actually make — the old list included 15 and 18 mm, which no one makes." }, { "kind": "product", "name": "Rockwool Flexi Slab (≥140mm)", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.035, "thickness_mm": 140, "source": "https://www.rockwool.com/uk/products/flexi/", "sourceUrl": "https://www.rockwool.com/uk/products/flexi/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "CORRECTED 2026-07-07: band boundary is 140mm (not 100mm); 0.035 applies ≥140mm. | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Rockwool Flexi Slab (50–120mm)", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/products/flexi/", "sourceUrl": "https://www.rockwool.com/uk/products/flexi/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "CORRECTED 2026-07-07: Rockwool declares 0.038 for 50-120mm (previous 0.034 was wrong — looked like RainScreen Duo values). 0.035 only ≥140mm. | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Rockwool Full Fill Cavity Batt", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.037, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Water-repellent full-fill batt" }, { "kind": "product", "name": "Rockwool HardRock Multi-Fix DD", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.039, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dual-density flat-roof board, 160 kg/m³" }, { "kind": "product", "name": "Rockwool NyRock Cavity Slab 032", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/products/nyrock-cavity-slab-032/", "sourceUrl": "https://www.rockwool.com/uk/products/nyrock-cavity-slab-032/", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full/partial-fill masonry cavity + party walls; lowest-λ UK stone wool (NyRock process), A1." }, { "kind": "product", "name": "Rockwool NyRock Rainscreen 032", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.032, "thickness_mm": 150, "source": "https://www.rockwool.com/uk/products/nyrock-rainscreen-032/", "sourceUrl": "https://www.rockwool.com/uk/products/nyrock-rainscreen-032/", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Ventilated facade / rainscreen slab, A1, high-rise suitable." }, { "kind": "product", "name": "Rockwool RainScreen Duo (<90mm)", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.034, "thickness_mm": 75, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dual-density facade slab" }, { "kind": "product", "name": "Rockwool RainScreen Duo (≥90mm)", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.035, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "λ0.035 at ≥90mm" }, { "kind": "product", "name": "Rockwool Roll (loft)", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.044, "thickness_mm": 150, "source": "https://www.rockwool.com/uk/products/roll/", "sourceUrl": "https://www.rockwool.com/uk/products/roll/", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Stone wool loft roll (Roll / Twin Roll / Rollbatt), ceiling-level cold roofs." }, { "kind": "product", "name": "Rockwool RWA45", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.035, "thickness_mm": 50, "source": "https://www.rockwool.com/uk/products/rwa45/", "sourceUrl": "https://www.rockwool.com/uk/products/rwa45/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "45 kg/m³ multi-application slab, A1" }, { "kind": "product", "name": "Rockwool Thermal Frame Slab 32", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Timber-frame slab (ex-Frametherm 32)" }, { "kind": "product", "name": "Rockwool Thermal Insulation Cavity Slab 32", "manufacturer": "Rockwool", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.rockwool.com/uk/", "sourceUrl": "https://www.rockwool.com/uk/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity slab" }, { "kind": "product", "name": "Secil ecoCork Lime Render", "manufacturer": "Secil", "category": "finish", "subtype": "insulating_lime", "lambda": 0.1, "thickness_mm": 40, "source": "https://www.celticsustainables.co.uk/content/Secil/Secil%20Ecocork%20Datasheet.pdf", "sourceUrl": "https://www.celticsustainables.co.uk/content/Secil/Secil%20Ecocork%20Datasheet.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NHL + cork aggregate, ~900 kg/m³" }, { "kind": "product", "name": "Sheep Wool Insulation Comfort", "manufacturer": "Sheep Wool Insulation", "category": "insulation", "subtype": "sheep_wool", "lambda": 0.042, "thickness_mm": 100, "source": "https://www.sheepwoolinsulation.com/products/comfort/", "sourceUrl": "https://www.sheepwoolinsulation.com/products/comfort/", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Sheep wool roll (Ireland, sold UK); manufacturer page states thermal conductivity '0.042W/m2k' (sic – unit typo on the page, the figure is λ), density 14 kg/m³." }, { "kind": "product", "name": "Sika Sarnafil G 410-15 EL (PVC, 1.5 mm)", "manufacturer": "Sika Sarnafil", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.17, "thickness_mm": 1.5, "source": "https://grc.sika.com/dms/getdocument.get/50d488ce-4989-45e8-9e69-57412723b1e4/010905052000151001_Sarnafil_G_410_15_EL_eng.pdf", "sourceUrl": "https://grc.sika.com/dms/getdocument.get/50d488ce-4989-45e8-9e69-57412723b1e4/010905052000151001_Sarnafil_G_410_15_EL_eng.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Glass-fleece reinforced PVC single-ply roof waterproofing for adhered/loose-laid warm and inverted roofs. PDS (Nov 2019): effective thickness 1.5 mm (-5/+10 %); mass 1.84 kg/m²; water vapour transmission µ = 15,000 (EN 1931). No declared λ — thermally negligible, modelled at the ISO 10456 generic PVC value 0.17 W/mK. Mark it as the waterproofing layer in an inverted roof." }, { "kind": "product", "name": "Sika Sarnafil G 410-18 EL (PVC, 1.8 mm)", "manufacturer": "Sika Sarnafil", "category": "membrane", "subtype": "roof_membrane", "lambda": 0.17, "thickness_mm": 1.8, "source": "https://gbr.sika.com/dms/getdocument.get/eff82981-56a6-3ea3-9cd4-902f7c4a5045/G410-18EL", "sourceUrl": "https://gbr.sika.com/dms/getdocument.get/eff82981-56a6-3ea3-9cd4-902f7c4a5045/G410-18EL", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "UK PDS (May 2017): PVC with glass non-woven inlay; effective thickness 1.8 mm (-5/+10 %); mass 2.2 kg/m²; µ = 15,000 (EN 1931). No declared λ — modelled at the ISO 10456 generic PVC value 0.17 W/mK." }, { "kind": "product", "name": "Siniat GTEC dB Board", "manufacturer": "Siniat", "category": "board", "subtype": "plasterboard", "lambda": 0.25, "thickness_mm": 12.5, "source": "https://www.siniat.co.uk", "sourceUrl": "https://www.siniat.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Acoustic board" }, { "kind": "product", "name": "Siniat GTEC Standard Board", "manufacturer": "Siniat", "category": "board", "subtype": "plasterboard", "lambda": 0.19, "thickness_mm": 12.5, "source": "https://www.siniat.co.uk", "sourceUrl": "https://www.siniat.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Standard plasterboard" }, { "kind": "product", "name": "SmartPly OSB3", "manufacturer": "MEDITE SMARTPLY", "category": "board", "subtype": "sheathing_board", "lambda": 0.13, "thickness_mm": 18, "source": "https://mdfosb.com", "sourceUrl": "https://mdfosb.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Structural OSB/3 (EN 13986)" }, { "kind": "product", "name": "SOPRATHERM CW4000 FF (Celotex CW4000 FF) (140mm)", "manufacturer": "Celotex (Soprema)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 140, "source": "https://www.soprema.co.uk/products/sopratherm-cw4000-ff", "sourceUrl": "https://www.soprema.co.uk/products/sopratherm-cw4000-ff", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "140 mm variant declared 0.021 W/mK. Same product/facing as the 90–115 mm entry." }, { "kind": "product", "name": "SOPRATHERM CW4000 FF (Celotex CW4000 FF) (90–115mm)", "manufacturer": "Celotex (Soprema)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 115, "source": "https://www.soprema.co.uk/products/sopratherm-cw4000-ff", "sourceUrl": "https://www.soprema.co.uk/products/sopratherm-cw4000-ff", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity PIR, T&G, alu-kraft foil both faces, 1190 × 450 (1205 × 465 incl. T&G), 10 mm nominal residual cavity, BBA certified. Page: 'declared thermal conductivity of 0.022 W/mK' for 90 and 115 mm; 140 mm is 0.021 W/mK. Formerly Celotex CW4000 FF – the Celotex range is now branded SOPRATHERM." }, { "kind": "product", "name": "Spaceloft", "manufacturer": "Aspen Aerogels", "category": "insulation", "subtype": "aerogel", "lambda": 0.014, "thickness_mm": 10, "source": "https://www.buyaerogel.com/product/spaceloft/", "sourceUrl": "https://www.buyaerogel.com/product/spaceloft/", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Flexible aerogel composite blanket. Aspen now markets Spaceloft for subsea pipework; the aerogel blanket sold for UK building work is A. Proctor Spacetherm" }, { "kind": "product", "name": "Spacetherm (aerogel blanket)", "manufacturer": "A. Proctor Group", "category": "insulation", "subtype": "aerogel", "lambda": 0.015, "thickness_mm": 10, "source": "https://proctorgroup.com/products/spacetherm", "sourceUrl": "https://proctorgroup.com/products/spacetherm", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Silica aerogel/fibre blanket" }, { "kind": "product", "name": "Spacetherm A2", "manufacturer": "A. Proctor Group", "category": "insulation", "subtype": "aerogel", "lambda": 0.019, "thickness_mm": 10, "source": "https://files.proctorgroup.com/assets/datasheets/proctors-spacetherm-slentex-a2-datasheet.pdf", "sourceUrl": "https://files.proctorgroup.com/assets/datasheets/proctors-spacetherm-slentex-a2-datasheet.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "A2 fire-rated aerogel blanket" }, { "kind": "product", "name": "Spray foam — closed cell (generic)", "manufacturer": "Generic", "category": "insulation", "subtype": "spray_foam", "lambda": 0.026, "thickness_mm": 75, "source": "https://www.bbacerts.co.uk (typical closed-cell PU declarations 0.025–0.028)", "sourceUrl": "https://www.bbacerts.co.uk (typical closed-cell PU declarations 0.025–0.028)", "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Closed-cell polyurethane, moderate vapour resistance (μ≈60). Use the installed product’s BBA-declared λ." }, { "kind": "product", "name": "Spray foam — open cell (generic)", "manufacturer": "Generic", "category": "insulation", "subtype": "spray_foam", "lambda": 0.039, "thickness_mm": 100, "source": "https://www.bbacerts.co.uk (typical open-cell PU declarations 0.037–0.040)", "sourceUrl": "https://www.bbacerts.co.uk (typical open-cell PU declarations 0.037–0.040)", "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Open-cell polyurethane (Icynene-type), vapour-OPEN (μ≈3). Use the installed product’s BBA-declared λ. Note lender/RICS caution on spray foam in roofs — always pair with the condensation check." }, { "kind": "product", "name": "Springvale Beamshield Plus (white EPS T-block)", "manufacturer": "Springvale EPS", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 228, "source": "https://springvale.com/wp-content/uploads/2024/06/BBA-07-4411-PS1-issue3-Beamshield-Plus-Dated-22-05-24.pdf", "sourceUrl": "https://springvale.com/wp-content/uploads/2024/06/BBA-07-4411-PS1-issue3-Beamshield-Plus-Dated-22-05-24.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 07/4411 PS1 issue 3 Table 1: Beamshield Plus (white) declared thermal conductivity 0.038 W/mK. T-shaped block spanning between and over the beams, overall thickness 228–450 mm (range only — thickness left free); toe (over-beam) thickness 63–220 mm depending on beam size. Model as EPS between beams (bridged by the beams) plus a continuous EPS toe layer over them; the certificate's Table 7 U-values include the beams." }, { "kind": "product", "name": "Springvale Ecobead Platinum", "manufacturer": "Springvale EPS", "category": "insulation", "subtype": "blown_bead", "lambda": 0.033, "thickness_mm": 100, "source": "https://springvale.com/ecobead/", "sourceUrl": "https://springvale.com/ecobead/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown graphite/EPS bead full-fill" }, { "kind": "product", "name": "Springvale Platinum Beamshield Plus (grey EPS T-block)", "manufacturer": "Springvale EPS", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 228, "source": "https://springvale.com/wp-content/uploads/2024/06/BBA-07-4411-PS1-issue3-Beamshield-Plus-Dated-22-05-24.pdf", "sourceUrl": "https://springvale.com/wp-content/uploads/2024/06/BBA-07-4411-PS1-issue3-Beamshield-Plus-Dated-22-05-24.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 07/4411 PS1 issue 3 Table 1: Platinum Beamshield Plus (grey) declared thermal conductivity 0.030 W/mK. Same geometry as Beamshield Plus (228–450 mm overall, toe 63–220 mm). Model as EPS between beams plus a continuous toe layer; certificate U-values include the beams." }, { "kind": "product", "name": "SPS Envirowall EWI EPS 70 (grey)", "manufacturer": "SPS Envirowall", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/BBA-Certificate-17-5447-Product-Sheet-2-TS-Rail-EPS-for-Timber-Frame-Mineral-Wool.pdf", "sourceUrl": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/BBA-Certificate-17-5447-Product-Sheet-2-TS-Rail-EPS-for-Timber-Frame-Mineral-Wool.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 17/5447 PS2: grey EPS 70, Class E to BS EN 13163:2012, λD 0.032 W/mK, nominal density 15–20 kg/m³, 60–200 mm in 10 mm increments." }, { "kind": "product", "name": "SPS Envirowall EWI EPS 70 (white)", "manufacturer": "SPS Envirowall", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/BBA-Certificate-17-5447-Product-Sheet-2-TS-Rail-EPS-for-Timber-Frame-Mineral-Wool.pdf", "sourceUrl": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/BBA-Certificate-17-5447-Product-Sheet-2-TS-Rail-EPS-for-Timber-Frame-Mineral-Wool.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 17/5447 PS2 (Envirowall TS Rail system): white EPS 70, Class E to BS EN 13163:2012, λD 0.038 W/mK, nominal density 15–20 kg/m³, 50–200 mm in 10 mm increments (20/30/40 mm for reveals), compressive ≥70 kPa." }, { "kind": "product", "name": "SPS Envirowall EWI mineral wool dual density (Direct Fix)", "manufacturer": "SPS Envirowall", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/Direct-Fix-MW-BBA-17-5447.pdf", "sourceUrl": "https://spsenvirowall.co.uk/wp-content/uploads/2021/06/Direct-Fix-MW-BBA-17-5447.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 17/5447 (Envirowall Direct Fix MW): Rockwool dual-density (MWDD) slabs, 'thermal conductivity (λD value) 0.036 W/mK', nominal densities 160/100 kg/m³ (outer/inner), 60–200 mm (20–50 mm for reveals), compressive ≥20 kPa, BS EN 13162:2012." }, { "kind": "product", "name": "Steico Base", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.048, "thickness_mm": 40, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_base_EUR_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_base_EUR_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "High-compression floor/flat-roof wood-fibre board; TDS: 'Declared thermal conductivity 0.048 W/(m*K)', density ~250 kg/m³, μ 5, cp 2100 J/kgK." }, { "kind": "product", "name": "Steico Flex 036", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.steico.com/uk/products/insulation/", "sourceUrl": "https://www.steico.com/uk/products/insulation/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flexible wood-fibre batt" }, { "kind": "product", "name": "Steico Flex 038", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.steico.com/uk/products/insulation/", "sourceUrl": "https://www.steico.com/uk/products/insulation/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Flexible wood-fibre batt" }, { "kind": "product", "name": "Steico Internal", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 60, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_internal_EUR_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_internal_EUR_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Internal wall insulation board (render-carrying, capillary-active); TDS: 'Declared thermal conductivity 0.038 W/(m*K)', density ~160 kg/m³, μ 5, cp 2100 J/kgK." }, { "kind": "product", "name": "Steico Protect Dry Type H", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.043, "thickness_mm": 80, "source": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "ETICS render-carrying wood-fibre board; datasheet: 'Type H dry: 0,043' W/(m·K), density approx. 180 kg/m³, μ 3, cp 2100 J/kgK." }, { "kind": "product", "name": "Steico Protect Dry Type L (037)", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.037, "thickness_mm": 100, "source": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "ETICS render-carrying wood-fibre board, dry process; datasheet: 'Type L dry/037: 0,037' W/(m·K), density approx. 110 kg/m³, μ 3, cp 2100 J/kgK. Different from the wet-process Protect H already in the library. Thickness list is for the whole Protect dry range – check type availability per thickness." }, { "kind": "product", "name": "Steico Protect Dry Type M", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.04, "thickness_mm": 100, "source": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/2._Product_information_ETICS_and_render_carrying_boards/STEICOprotect_dry_TM_INT_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "ETICS render-carrying wood-fibre board; datasheet: 'Type M dry: 0,040' W/(m·K), density approx. 140 kg/m³, μ 3, cp 2100 J/kgK." }, { "kind": "product", "name": "Steico Protect H (dry process)", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.043, "thickness_mm": 80, "source": "https://www.steico.com/uk/products/insulation/", "sourceUrl": "https://www.steico.com/uk/products/insulation/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Render-carrying ETICS board. VARIANT-SPECIFIC λ: Protect L dry 0.037, M dry 0.040, H dry 0.043, wet-process H 0.048 — pick the actual variant (clarified 2026-07-07)." }, { "kind": "product", "name": "Steico Special Dry", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.04, "thickness_mm": 100, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/DNK_da/DNK_en_Technical_Data_Sheets/STEICO_technical-data-sheet_special-dry_DNK_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/DNK_da/DNK_en_Technical_Data_Sheets/STEICO_technical-data-sheet_special-dry_DNK_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Combined sheathing and render-carrying board (dry process); TDS: declared thermal conductivity 0.040 W/(m*K), density ~140 kg/m³, μ 3, cp 2100 J/kgK. Constant λ across thicknesses. (English TDS on steico.com, DK edition.)" }, { "kind": "product", "name": "Steico Therm", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm_EUR_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm_EUR_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rigid wet-process wood-fibre board, WF-EN 13171-T4-CS(10\\Y)50-TR2,5-WS2,0-AFr100; TDS: 'Declared thermal conductivity 0.038 W/(m*K)', density ~160 kg/m³, μ 5, cp 2100 J/kgK. Vapour-open." }, { "kind": "product", "name": "Steico Therm Dry", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.037, "thickness_mm": 100, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm-dry_EUR_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm-dry_EUR_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Multifunctional dry-process rigid wood-fibre board; TDS: 'Declared thermal conductivity 0.037 W/(m*K)', density ~110 kg/m³, μ 3, cp 2100 J/kgK. Constant λ across thicknesses." }, { "kind": "product", "name": "Steico Therm SD", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 20, "source": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm-sd_EUR_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Public_Docs/EUR_en/EUR_en_Technical_Data_Sheets/1._Product_information_wood_fibre_insulation/STEICO_technical-data-sheet_therm-sd_EUR_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Thermal + impact-sound floor insulation board; TDS: 'Declared thermal conductivity 0.038 W/(m*K)', density ~150 kg/m³, μ 5, cp 2100 J/kgK." }, { "kind": "product", "name": "Steico Universal", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.048, "thickness_mm": 60, "source": "https://www.steico.com/uk/products/insulation/", "sourceUrl": "https://www.steico.com/uk/products/insulation/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Rigid sarking board, ~270 kg/m³" }, { "kind": "product", "name": "Steico Universal Dry (sarking)", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.043, "thickness_mm": 52, "source": "https://cdn.shopify.com/s/files/1/0222/7290/1216/files/STEICO_technical-data-sheet_universal-dry_EUR_en_i.pdf", "sourceUrl": "https://cdn.shopify.com/s/files/1/0222/7290/1216/files/STEICO_technical-data-sheet_universal-dry_EUR_en_i.pdf", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Vapour-open sarking/racking board, 180–210 kg/m³, μ 3, sd 0.11–0.30 m (0.045 @35mm)." }, { "kind": "product", "name": "Steico Zell (blown wood fibre)", "manufacturer": "Steico", "category": "insulation", "subtype": "wood_fibre", "lambda": 0.038, "thickness_mm": 200, "source": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/3._Product_information_Air-injected_insulations/STEICOzell_TM_INT_en_i.pdf", "sourceUrl": "https://www.steico.com/fileadmin/user_upload/Euro_Media/Downloads/3._Product_information_Air-injected_insulations/STEICOzell_TM_INT_en_i.pdf", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Air-injected loose wood-fibre insulation; datasheet: 'Declared thermal conductivity [W/(m*K)] 0.038'; installed density approx. 32 kg/m³ open-blown attic floor, approx. 35–45 kg/m³ in closed cavities; μ 1–2; cp 2100 J/kgK. Blown to depth – thickness free (listed depths are typical)." }, { "kind": "product", "name": "Sto StoTherm Classic EWI EPS (white)", "manufacturer": "Sto", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090331.pdf", "sourceUrl": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090331.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NSAI Agrément 09/0331 (StoTherm EWI systems): expanded polystyrene board 'standard white 0.038 W/mK', density 15 or 19 kg/m³, 50–150 mm. CHECK CURRENT SUPPLY: Sto Ltd (UK) showed an administration notice on sto.co.uk in Sept 2026 and BBA 95/3132 could not be opened." }, { "kind": "product", "name": "Sto StoTherm Classic EWI EPS graphite (grey)", "manufacturer": "Sto", "category": "insulation", "subtype": "EPS", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090331.pdf", "sourceUrl": "https://www.nsai.ie/images/uploads/certification-agrement/IAB090331.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NSAI Agrément 09/0331: 'graphite enhanced grey 0.036 W/mK', density 15 or 19 kg/m³, 50–150 mm. Older declaration — see the white-EPS note about Sto Ltd UK." }, { "kind": "product", "name": "Stowell Dense Concrete 10.4N", "manufacturer": "Stowell Concrete", "category": "masonry", "subtype": "dense_block", "lambda": 1.39, "thickness_mm": 100, "source": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-bricks-10-3n-mm2", "sourceUrl": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-bricks-10-3n-mm2", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "1.39 inner, 1.49 outer" }, { "kind": "product", "name": "Stowell Dense Concrete 17.5N", "manufacturer": "Stowell Concrete", "category": "masonry", "subtype": "dense_block", "lambda": 1.46, "thickness_mm": 100, "source": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-17-5n-mm2", "sourceUrl": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-17-5n-mm2", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "1.46 inner, 1.56 outer" }, { "kind": "product", "name": "Stowell Dense Concrete 7.3N", "manufacturer": "Stowell Concrete", "category": "masonry", "subtype": "dense_block", "lambda": 1.33, "thickness_mm": 100, "source": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-7-3n-mm2", "sourceUrl": "https://www.stowellconcrete.co.uk/stowell-concrete-products/dense-concrete-blocks-7-3n-mm2", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "1.33 inner (3% MC), 1.43 outer" }, { "kind": "product", "name": "Stowell Stowlite Medium 7.3N", "manufacturer": "Stowell Concrete", "category": "masonry", "subtype": "medium_block", "lambda": 0.63, "thickness_mm": 100, "source": "https://www.stowellconcrete.co.uk/stowell-concrete-products/stowlite-medium-dense-blocks-bricks-7-3n-mm2", "sourceUrl": "https://www.stowellconcrete.co.uk/stowell-concrete-products/stowlite-medium-dense-blocks-bricks-7-3n-mm2", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Medium-dense aggregate. CORRECTED 2026-07-07: manufacturer declares 0.63 @3% MC inner / 0.67 exposed (stored 0.51 was too optimistic). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Straw bale (generic)", "manufacturer": "Generic (natural)", "category": "insulation", "subtype": "straw", "lambda": 0.065, "thickness_mm": 450, "source": "Published straw-bale studies/certifications 0.055–0.080 by orientation/density", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Load-bearing or infill straw bale walling; render both faces. Vapour-open." }, { "kind": "product", "name": "Superglass Multi-Roll 44", "manufacturer": "Superglass", "category": "insulation", "subtype": "glass_wool", "lambda": 0.044, "thickness_mm": 150, "source": "https://www.superglass.co.uk/products/multi-roll-44", "sourceUrl": "https://www.superglass.co.uk/products/multi-roll-44", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "General-purpose loft roll (Stirling-made glass wool)." }, { "kind": "product", "name": "Superglass Superwall 32", "manufacturer": "Superglass", "category": "insulation", "subtype": "fibre_batt", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.superglass.co.uk", "sourceUrl": "https://www.superglass.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "BBA glass wool cavity batt; full/partial fill" }, { "kind": "product", "name": "Superglass Superwall 34 Cavity Wall Batt", "manufacturer": "Superglass", "category": "insulation", "subtype": "fibre_batt", "lambda": 0.034, "thickness_mm": 100, "source": "https://www.superglass.co.uk/products/superwall-34-cavity-wall-batt", "sourceUrl": "https://www.superglass.co.uk/products/superwall-34-cavity-wall-batt", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Full-fill cavity batt (Superwall 32/36 already listed)." }, { "kind": "product", "name": "Superglass Superwall 36", "manufacturer": "Superglass", "category": "insulation", "subtype": "fibre_batt", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.superglass.co.uk", "sourceUrl": "https://www.superglass.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Glass wool cavity batt; full/partial fill" }, { "kind": "product", "name": "Superglass Timber & Rafter Roll 32", "manufacturer": "Superglass", "category": "insulation", "subtype": "glass_wool", "lambda": 0.032, "thickness_mm": 140, "source": "https://www.superglass.co.uk/products/timber-rafter-roll-32", "sourceUrl": "https://www.superglass.co.uk/products/timber-rafter-roll-32", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Timber frame walls and rafters (their 35-grade also exists)." }, { "kind": "product", "name": "Tarmac Hemelite Coursing Brick", "manufacturer": "Tarmac", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.57, "thickness_mm": 65, "source": "https://www.tarmac.com/products/blocks/hemelite-coursing-bricks", "sourceUrl": "https://www.tarmac.com/products/blocks/hemelite-coursing-bricks", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Medium-density aggregate coursing brick, 1450 kg/m3. Tarmac product page now quotes 0.57 W/mK (was 0.51 here; updated 15 Sep 2026)." }, { "kind": "product", "name": "Tarmac Hemelite Standard", "manufacturer": "Tarmac", "category": "masonry", "subtype": "medium_block", "lambda": 0.57, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/hemelite-standard/", "sourceUrl": "https://www.tarmac.com/products/blocks/hemelite-standard/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Medium-dense lightweight aggregate. CORRECTED 2026-07-07: Tarmac guide @3% MC — 3.6N 0.45, 7.3N 0.47, 10.4N 0.49 (stored 0.57 not found in any current Tarmac literature). | Rob 2026-07-08: 0.57 (reverted to original)." }, { "kind": "product", "name": "Tarmac Topcrete Standard", "manufacturer": "Tarmac", "category": "masonry", "subtype": "dense_block", "lambda": 1.07, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/topcrete-standard/", "sourceUrl": "https://www.tarmac.com/products/blocks/topcrete-standard/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dense aggregate 7.3N solid" }, { "kind": "product", "name": "Tarmac Topflow Screed A ThermioMAX (anhydrite)", "manufacturer": "Tarmac", "category": "screed", "subtype": "screed", "lambda": 2.5, "thickness_mm": 40, "source": "https://www.tarmac.com/wp-content/plugins/tarmac.com/components/downloads/file-download.php?download_id=7592", "sourceUrl": "https://www.tarmac.com/wp-content/plugins/tarmac.com/components/downloads/file-download.php?download_id=7592", "retrieved": "2026-09-16", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Tarmac-supplied Gyvlon ThermioMAX FD E2C (Topflow Screed A family). Datasheet SBN0226 (Feb 2026): 'λ=2,5 W/m.K'; the BBA-guaranteed minimum is 2.3 W/m.K for approved UK plants; wet 2200 / dry 2000 kg/m³; C30 F8; min bonded 20/25 mm, floating 30/35 mm, 15 mm over UFH pipes floating / 10 bonded." }, { "kind": "product", "name": "Tarmac Toplite GTi", "manufacturer": "Tarmac", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/toplite-gti/", "sourceUrl": "https://www.tarmac.com/products/blocks/toplite-gti/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "2.9N, 460 kg/m³" }, { "kind": "product", "name": "Tarmac Toplite Standard", "manufacturer": "Tarmac", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.16, "thickness_mm": 100, "source": "https://www.tarmac.com/products/blocks/toplite-standard/", "sourceUrl": "https://www.tarmac.com/products/blocks/toplite-standard/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N, ~630 kg/m³" }, { "kind": "product", "name": "Thatch — combed wheat reed", "manufacturer": "Generic (natural)", "category": "insulation", "subtype": "thatch", "lambda": 0.07, "thickness_mm": 350, "source": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "sourceUrl": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "retrieved": "2026-07-06", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "λ0.07 per CIBSE Guide A3" }, { "kind": "product", "name": "Thatch — long straw", "manufacturer": "Generic (natural)", "category": "insulation", "subtype": "thatch", "lambda": 0.07, "thickness_mm": 350, "source": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "sourceUrl": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "retrieved": "2026-07-06", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "λ0.07 per CIBSE Guide A3" }, { "kind": "product", "name": "Thatch — water reed", "manufacturer": "Generic (natural)", "category": "insulation", "subtype": "thatch", "lambda": 0.09, "thickness_mm": 350, "source": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "sourceUrl": "https://www.thatchadvicecentre.co.uk/thatch-information/technical-information/building-regulations", "retrieved": "2026-07-06", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "λ0.09 per CIBSE Guide A3 (used by UK building control)" }, { "kind": "product", "name": "Thermabead CarbonSaver", "manufacturer": "Thermabead", "category": "insulation", "subtype": "blown_bead", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.thermabead.co.uk/new-build", "sourceUrl": "https://www.thermabead.co.uk/new-build", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Blown EPS bead full-fill cavity" }, { "kind": "product", "name": "Thermafleece CosyWool", "manufacturer": "Thermafleece", "category": "insulation", "subtype": "sheep_wool", "lambda": 0.039, "thickness_mm": 100, "source": "https://thermafleece.com", "sourceUrl": "https://thermafleece.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "75% British wool, 18 kg/m³" }, { "kind": "product", "name": "Thermafleece UltraWool", "manufacturer": "Thermafleece", "category": "insulation", "subtype": "sheep_wool", "lambda": 0.035, "thickness_mm": 70, "source": "https://thermafleece.com", "sourceUrl": "https://thermafleece.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "High-density wool blend, 31 kg/m³" }, { "kind": "product", "name": "Thermalite Coursing Brick", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.15, "thickness_mm": 65, "source": "https://www.forterra.co.uk", "sourceUrl": "https://www.forterra.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Aircrete coursing brick" }, { "kind": "product", "name": "Thermalite Hi-Strength Trenchblock", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.16, "thickness_mm": 300, "source": "https://www.forterra.co.uk", "sourceUrl": "https://www.forterra.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "7.3N foundation trenchblock. CORRECTED 2026-07-07: Forterra datasheet gives 0.18 above DPC and 0.29 below DPC (5% moisture) — a trenchblock usually sits BELOW DPC, so use 0.29 for foundation positions. | Rob 2026-07-08: 0.16." }, { "kind": "product", "name": "Thermalite Party Wall", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.16, "thickness_mm": 100, "source": "https://www.forterra.co.uk/product/thermalite-aircrete-party-wall/", "sourceUrl": "https://www.forterra.co.uk/product/thermalite-aircrete-party-wall/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "4N separating-wall aircrete" }, { "kind": "product", "name": "Thermalite Shield", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.15, "thickness_mm": 100, "source": "https://www.forterra.co.uk", "sourceUrl": "https://www.forterra.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N aircrete" }, { "kind": "product", "name": "Thermalite Trench Block", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.23, "thickness_mm": 275, "source": "http://www.greenspec.co.uk/green-products/strip-foundation-blockwork/details/thermalite-trenchblock/", "sourceUrl": "http://www.greenspec.co.uk/green-products/strip-foundation-blockwork/details/thermalite-trenchblock/", "retrieved": "2026-07-06", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "0.15 above DPC; 0.23 below ground (moisture)" }, { "kind": "product", "name": "Thermalite Turbo", "manufacturer": "Forterra", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.forterra.co.uk", "sourceUrl": "https://www.forterra.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "2.9N, ~470 kg/m³" }, { "kind": "product", "name": "Thermo-Hemp Combi Jute", "manufacturer": "HempFlax", "category": "insulation", "subtype": "hemp", "lambda": 0.04, "thickness_mm": 100, "source": "https://www.thermo-hanf.de", "sourceUrl": "https://www.thermo-hanf.de", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Hemp+jute batt. CORRECTED 2026-07-07: current TDS (Feb 2026) declares λD 0.038 (0.043 was the 2024 declaration). | Rob 2026-07-08: 0.040." }, { "kind": "product", "name": "Thomas Armstrong Airtec Standard", "manufacturer": "Thomas Armstrong", "category": "masonry", "subtype": "aircrete_block", "lambda": 0.11, "thickness_mm": 100, "source": "https://www.specifiedby.com/thomas-armstrong-group/airtec-standard", "sourceUrl": "https://www.specifiedby.com/thomas-armstrong-group/airtec-standard", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "3.6N large-format aircrete, ~470 kg/m³." }, { "kind": "product", "name": "Thomas Armstrong Insulite", "manufacturer": "Thomas Armstrong", "category": "masonry", "subtype": "medium_block", "lambda": 0.49, "thickness_mm": 100, "source": "https://www.thomasarmstrongconcreteblocks.co.uk/lightweight-dense-concrete-blocks/insulite", "sourceUrl": "https://www.thomasarmstrongconcreteblocks.co.uk/lightweight-dense-concrete-blocks/insulite", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Medium-dense (1450-1550 kg/m³). CORRECTED 2026-07-07: current TA data — 0.49 protected / 0.54 exposed (stored 0.42/0.45 was superseded NBS data). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Thomas Armstrong Solid Dense", "manufacturer": "Thomas Armstrong", "category": "masonry", "subtype": "dense_block", "lambda": 1.17, "thickness_mm": 100, "source": "https://www.thomasarmstrongconcreteblocks.co.uk", "sourceUrl": "https://www.thomasarmstrongconcreteblocks.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dense aggregate; 1.17 inner, 1.26 outer" }, { "kind": "product", "name": "Thomas Armstrong Ultralite", "manufacturer": "Thomas Armstrong", "category": "masonry", "subtype": "lightweight_block", "lambda": 0.32, "thickness_mm": 100, "source": "https://source.thenbs.com/product/ultralite-concrete-block", "sourceUrl": "https://source.thenbs.com/product/ultralite-concrete-block", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Lightweight aggregate 7.3N; 0.32 inner" }, { "kind": "product", "name": "Ty-Mawr Sublime Glapor (limecrete)", "manufacturer": "Ty-Mawr", "category": "insulation", "subtype": "foam_glass", "lambda": 0.078, "thickness_mm": 150, "source": "https://www.lime.org.uk", "sourceUrl": "https://www.lime.org.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Foamed recycled glass for insulated limecrete floors" }, { "kind": "product", "name": "UF foam cavity fill (injected, existing walls)", "manufacturer": "Generic", "category": "insulation", "subtype": "spray_foam", "lambda": 0.038, "thickness_mm": 50, "source": "BRE / historic BBA urea-formaldehyde foam declarations 0.036–0.040", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Urea-formaldehyde injected cavity foam — common in 1970s–80s retrofits; useful when appraising an EXISTING element. Friable and vapour-open (μ≈3; BS 5250 resistivity implies ~4)." }, { "kind": "product", "name": "Unilin CavityTherm (full-fill)", "manufacturer": "Unilin (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/products/cavitytherm/ct-pir-cavitytherm/", "sourceUrl": "https://unilininsulation.co.uk/products/cavitytherm/ct-pir-cavitytherm/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "FULL-FILL cavity PIR with drainage-plane facing; λ0.021" }, { "kind": "product", "name": "Unilin Safe-R (Xtratherm)", "manufacturer": "Unilin (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.02, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/products/safe-r/", "sourceUrl": "https://unilininsulation.co.uk/products/safe-r/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Phenolic, λ from 0.020" }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/CW Partial Fill Cavity", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019CW_January2026_v1.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019CW_January2026_v1.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/CW brochure, January 2026 v1: thermal conductivity 0.019 W/mK, compressive strength 100 (kPa), manufactured to EN 13166, board 1200 x 450, rigid phenolic core between composite foil facings. R 75mm 3.90 / 80 4.20 / 100 5.25 / 120 6.30 m2K/W - single lambda, no banding. PARTIAL FILL: brochure requires a 50 mm residual cavity to suit all exposure zones (25 mm minimum in isolated circumstances) - model the residual cavity as its own air layer, low-e on the board side. Reaction to fire Euroclass D-s1,d0, the lowest in the 019 range (the MA boards are C-s2,d0, TB-MF and STP are B-s1,d0). Density not declared - phenolic class value used." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/MA (Floors)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MAFloors_January2026_v1.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MAFloors_January2026_v1.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/MA (Floors) brochure, January 2026 v1: '0.019 W/mK', compressive strength 100 kPa, Euroclass C s2,d0, 2400 x 1200, composite foil facings both sides, manufactured to EN 13166. R 75mm 3.90 / 80 4.20 / 100 5.25 / 120 6.30 / 150 7.85. Ground-supported and suspended floors, suitable under underfloor heating; perimeter strips available. SR019/MA is ONE multi-application board (Unilin code 25YD19SR) sold against four January-2026 brochures - framing, floors, roofs and soffit - so those four entries share a lambda, a board size and a thickness list. The stock table lists 75/80/100 (120 and 150 appear in the R-value tables); other thicknesses to order. Density is not declared - thermal mass falls back to the phenolic class value (35 kg/m3)." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/MA (Framing)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2026/01/UK_SR019MA-Framing_January2026_v1-reduced-size.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2026/01/UK_SR019MA-Framing_January2026_v1-reduced-size.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/MA (Framing) brochure, January 2026 v1: 'Thermal Conductivity 0.019 W/mK', EN 13166:2012+A1:2015, compressive strength 100 kPa, Reaction to Fire Euroclass C s2,d0, board 2400 x 1200, rigid phenolic core between composite foil facings (low-emissivity). R-values 75mm 3.90 / 80 4.20 / 100 5.25 / 120 6.30 / 150 7.85 m2K/W. Between or over studs on timber or steel frame, timber frame up to 11 m. SR019/MA is ONE multi-application board (Unilin code 25YD19SR) sold against four January-2026 brochures - framing, floors, roofs and soffit - so those four entries share a lambda, a board size and a thickness list. The stock table lists 75/80/100 (120 and 150 appear in the R-value tables); other thicknesses to order. Density is not declared - thermal mass falls back to the phenolic class value (35 kg/m3)." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/MA (Roofs)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MARoofs_January2026_v2.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MARoofs_January2026_v2.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/MA (Roofs) brochure, January 2026 v2: 'Thermal Conductivity 0.019 W/mK', 'Compressive Strength 100 kPa', Euroclass C s2,d0, 2400 x 1200, phenolic core between composite foil facings. R 75mm 3.90 / 80 4.20 / 100 5.25 / 150 7.85. Pitched roofs above, between or below rafters. SR019/MA is ONE multi-application board (Unilin code 25YD19SR) sold against four January-2026 brochures - framing, floors, roofs and soffit - so those four entries share a lambda, a board size and a thickness list. The stock table lists 75/80/100 (120 and 150 appear in the R-value tables); other thicknesses to order. Density is not declared - thermal mass falls back to the phenolic class value (35 kg/m3)." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/MA (Soffit)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MASoffit_January2026_v1.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019MASoffit_January2026_v1.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/MA (Soffit) brochure, January 2026 v1: 'Thermal Conductivity 0.019 W/mK', 'Compressive Strength 100 kPa', Euroclass C s2,d0, 2400 x 1200, foil-faced finish. R 75mm 3.90 / 80 4.20 / 100 5.25 / 120 6.30. Soffit of structural ceilings, exposed floors over unheated space. SR019/MA is ONE multi-application board (Unilin code 25YD19SR) sold against four January-2026 brochures - framing, floors, roofs and soffit - so those four entries share a lambda, a board size and a thickness list. The stock table lists 75/80/100 (120 and 150 appear in the R-value tables); other thicknesses to order. Density is not declared - thermal mass falls back to the phenolic class value (35 kg/m3)." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/STP Soffit Plus (phenolic core)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019STP_January2026_v1.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019STP_January2026_v1.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/STP brochure, January 2026 v1: 'Thermal Conductivity 0.019 (W/mK)', EN 13166:2012+A1:2015, Euroclass B-s1,d0, board 2400 x 1200. Soffit Plus = the SR019 phenolic core bonded to a 6 mm building panel (a tougher, decorable soffit face than plain foil), so the overall board is 81 / 86 / 106 / 126 mm for a 75 / 80 / 100 / 120 mm core. THE STORED THICKNESS IS THE PHENOLIC CORE ONLY - the brochure R-values (3.90 / 4.20 / 5.25 / 6.30) are core-only too, and it declares no lambda for the 6 mm panel, so it is not modelled; add it as its own layer only if you have a source for its lambda. Density not declared - phenolic class value used." }, { "kind": "product", "name": "Unilin Safe-R 019 SR019/TB-MF Insulated Plasterboard", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulated_pb", "subtype": "phenolic", "lambda": 0.019, "thickness_mm": 92.5, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019TB_MF_January2026_v1.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2025/12/UK_SR019TB_MF_January2026_v1.pdf", "retrieved": "2026-09-18", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "SR019/TB-MF brochure, January 2026 v1: 'Thermal Conductivity 0.019 W/mK', manufactured to EN 13950, Euroclass B-s1,d0, 2400 (UK) x 1200. Phenolic core between composite foil facings, bonded to 12.5 mm tapered-edge plasterboard; the foil back is the integral vapour control layer - seal and tape the joints. Core 75 / 80 / 100 mm gives overall 87.5 / 92.5 / 112.5 mm, overall R 4.00 / 4.25 / 5.30 m2K/W. MECHANICALLY FIXED (the -MF suffix) to battens or studs, newbuild and refurbishment. Auto-adds core + facing as two layers - set the core to (overall - 12.5 mm). Note the 019 laminate starts at 75 mm of phenolic; the older SR/TB-MF (lambda 0.020-0.023) covers the thin 37.5-82.5 mm sizes." }, { "kind": "product", "name": "Unilin Safe-R SR/FB Framing Board (100–150mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.02, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-FB-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-FB-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884. λ 0.020 W/mK for 100–150 mm." }, { "kind": "product", "name": "Unilin Safe-R SR/FB Framing Board (50–99mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-FB-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-FB-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884. Phenolic framing/rainscreen board (successor to SR/TF), perforated composite foil both sides, emissivity 0.05. Between studs or as sheathing on timber/steel frame; rainscreen on masonry. λ 0.021 W/mK 50–99 mm; 0.020 W/mK 100–150 mm. Euroclass C-s1,d0." }, { "kind": "product", "name": "Unilin Safe-R SR/PR Pitched Roof (100–150mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.02, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-PR-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-PR-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884 Table 5. Phenolic, perforated composite foil facing. λ 0.020 W/mK for 100–150 mm." }, { "kind": "product", "name": "Unilin Safe-R SR/PR Pitched Roof (50–99mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-PR-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-PR-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884 Table 5. Rigid phenolic, perforated composite foil facing both sides. Above/between/below rafters. Thickness-dependent λ: 50–99 mm 0.021 W/mK; 100–150 mm 0.020 W/mK. Core vapour resistivity 171 MNs/gm." }, { "kind": "product", "name": "Unilin Safe-R SR/UF Underfloor (100–150mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.02, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-UF-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-UF-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884. λ 0.020 W/mK for 100–150 mm. Sizes taken from the certificate's U-value tables." }, { "kind": "product", "name": "Unilin Safe-R SR/UF Underfloor (50–99mm)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "phenolic", "lambda": 0.021, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-UF-2024.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/07/BBA-23-6884-Unilin-Insulation-SR-UF-2024.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6884. Rigid phenolic floor board, perforated composite foil facing both sides. Ground-bearing, suspended concrete, between timber joists. λ 0.021 W/mK for 50–99 mm; 0.020 for 100–150 mm. Core vapour resistivity 171 MNs/gm." }, { "kind": "product", "name": "Unilin Thin-R (Xtratherm)", "manufacturer": "Unilin (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/products/thin-r/", "sourceUrl": "https://unilininsulation.co.uk/products/thin-r/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Foil-faced PIR range" }, { "kind": "product", "name": "Unilin Thin-R Plus XT/CWP Cavity Wall", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-CW-2026.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-CW-2026.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6997 (same cert as XT/CW). Partial-fill cavity board, composite foil both sides. 50–120 mm range (individual sizes not listed – thickness left free). Declared λ 0.021 W/mK." }, { "kind": "product", "name": "Unilin Thin-R Plus XT/HYF (Hybrid Floor)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.021, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2023/11/BBA-23-6997-Unilin-Insulation-XT-PR-UF-Floors-2023.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2023/11/BBA-23-6997-Unilin-Insulation-XT-PR-UF-Floors-2023.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6997 (same certificate as XT/PR-UF). Composite foil facing both sides. Floor board. 'Declared value (λD) 0.021 W·m–1·K–1'." }, { "kind": "product", "name": "Unilin Thin-R XT/CW (T&G) Cavity Wall", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 75, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-CW-2026.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-CW-2026.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6997. Partial-fill cavity board, tongue-and-groove, composite foil facing both sides, min 50 mm residual cavity. Certificate states a 40–125 mm thickness range (individual sizes not listed – thickness left free). Declared λ 0.022 W/mK, not thickness dependent. PIR core vapour resistivity 272 MNs/gm, facing 940 MNs/g." }, { "kind": "product", "name": "Unilin Thin-R XT/PR-UF (Pitched Roof & Floor)", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2023/11/BBA-23-6997-Unilin-Insulation-XT-PR-UF-Floors-2023.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2023/11/BBA-23-6997-Unilin-Insulation-XT-PR-UF-Floors-2023.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6997. Composite foil facing both sides. Same board sold for pitched roofs (between/over rafters) and ground/suspended floors. 'Declared value (λD) 0.022 W·m–1·K–1', not thickness dependent. PIR core vapour resistivity 300 MNs/gm, foil facer 7000 MNs/g." }, { "kind": "product", "name": "Unilin Thin-R XT/TF Timber Frame", "manufacturer": "Unilin Insulation (Xtratherm)", "category": "insulation", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 100, "source": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-TF-2026.pdf", "sourceUrl": "https://unilininsulation.co.uk/wp-content/uploads/sites/2/2024/06/BBA-23-6997-Unilin-Insulation-XT-TF-2026.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 23/6997. Composite foil facing both sides. Between studs, as internal lining or external sheathing of timber-frame walls. Range 25–150 mm; the listed sizes are those in the certificate's U-value tables. 'Declared value (λD) 0.022 W·m–1·K–1', thickness independent. Core vapour resistivity 272 MNs/gm." }, { "kind": "product", "name": "Unilin Thin-R XT/TL Thermal Liner", "manufacturer": "Unilin (Xtratherm)", "category": "insulated_pb", "subtype": "PIR", "lambda": 0.022, "thickness_mm": 52.5, "source": "https://unilininsulation.co.uk/products/thin-r/xt-tl-dd/", "sourceUrl": "https://unilininsulation.co.uk/products/thin-r/xt-tl-dd/", "retrieved": "2026-08-24", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Dot-and-dab thermal liner: PIR core λ0.022 + 12.5mm tapered-edge plasterboard, kraft/foil integral VCL. Remember the dab air gap (id 93) behind it." }, { "kind": "product", "name": "URSA Cavity Batt 32", "manufacturer": "URSA", "category": "insulation", "subtype": "fibre_batt", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.ursa.co.uk", "sourceUrl": "https://www.ursa.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Glass wool cavity slab; full/partial fill" }, { "kind": "product", "name": "URSA Cavity Batt 35", "manufacturer": "URSA", "category": "insulation", "subtype": "fibre_batt", "lambda": 0.035, "thickness_mm": 100, "source": "https://www.ursa.co.uk", "sourceUrl": "https://www.ursa.co.uk", "retrieved": "2026-07-06", "sourceType": "retailer", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Glass wool cavity slab; full/partial fill" }, { "kind": "product", "name": "Ursa XPS N-III-L (140–200mm)", "manufacturer": "Ursa", "category": "insulation", "subtype": "XPS", "lambda": 0.035, "thickness_mm": 140, "source": "https://www.ursa.co.uk", "sourceUrl": "https://www.ursa.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "CORRECTED 2026-07-07: 0.036 applies from 140mm (band boundary was wrongly stored as 80mm). | Rob 2026-07-08: 0.035 for 140-200mm; 240mm = 0.036." }, { "kind": "product", "name": "Ursa XPS N-III-L (30–120mm)", "manufacturer": "Ursa", "category": "insulation", "subtype": "XPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.ursa.co.uk", "sourceUrl": "https://www.ursa.co.uk", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "CORRECTED 2026-07-07: Ursa TDS (Jan 2024) declares 0.034 for the whole 30-120mm band. | Rob 2026-07-08: 0.032." }, { "kind": "product", "name": "va-Q-vip B", "manufacturer": "va-Q-tec", "category": "insulation", "subtype": "vip", "lambda": 0.007, "thickness_mm": 25, "source": "https://www.va-q-tec.com/en/products/va-q-vip/", "sourceUrl": "https://www.va-q-tec.com/en/products/va-q-vip/", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Design/aged ~0.007; initial ≤0.005. va-Q-vip B is no longer listed by va-Q-tec (current range va-Q-vip F / Floor / A2) — retained for assessing existing construction" }, { "kind": "product", "name": "Vacupor NT-B2-S", "manufacturer": "Porextherm (Morgan)", "category": "insulation", "subtype": "vip", "lambda": 0.007, "thickness_mm": 25, "source": "https://www.morganthermalceramics.com/media/sylfcwxj/vacupor-nt-b2-s-data-sheet-english-v2.pdf", "sourceUrl": "https://www.morganthermalceramics.com/media/sylfcwxj/vacupor-nt-b2-s-data-sheet-english-v2.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Design λ 0.0070; initial ≤0.0044. Source URL refreshed 2026-07-07 (Porextherm now Morgan Thermal Ceramics)." }, { "kind": "product", "name": "Versapanel A2 (cement particle)", "manufacturer": "Euroform", "category": "board", "subtype": "cement_board", "lambda": 0.55, "thickness_mm": 12, "source": "https://euroform.co.uk/wp-content/uploads/2023/11/Euroform-A2-Versapanel-Brochure-issue-8-11-2023.pdf", "sourceUrl": "https://euroform.co.uk/wp-content/uploads/2023/11/Euroform-A2-Versapanel-Brochure-issue-8-11-2023.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "A2 non-combustible, 1506-1590 kg/m³. CORRECTED 2026-07-07: Euroform brochure declares λ ≤0.55 (stored 0.15 was a transcription error; effect small at 12mm but wrong). | Rob 2026-07-08: OK." }, { "kind": "product", "name": "Vinyl / linoleum flooring", "manufacturer": "Generic", "category": "covering", "subtype": "floor_finish", "lambda": 0.17, "thickness_mm": 3, "source": "BS EN ISO 10456 Table 3 — plastics/linoleum floorcovering 0.17", "sourceUrl": null, "retrieved": "2026-08-24", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Negligible R; include for completeness of an in-use estimate." }, { "kind": "product", "name": "Visqueen VCL / AVCL", "manufacturer": "Visqueen", "category": "membrane", "subtype": "vcl", "lambda": 0.33, "thickness_mm": 0.5, "source": "https://visqueen.com/products/visqueen-vapour-check", "sourceUrl": "https://visqueen.com/products/visqueen-vapour-check", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Air & vapour control layer; negligible R | Rob 2026-07-08: assume lambda 0.33." }, { "kind": "product", "name": "Warmcel (cellulose)", "manufacturer": "CIUR", "category": "insulation", "subtype": "cellulose", "lambda": 0.038, "thickness_mm": 150, "source": "https://www.greenspec.co.uk/green-products/insulation-lofts/details/warmcel/", "sourceUrl": "https://www.greenspec.co.uk/green-products/insulation-lofts/details/warmcel/", "retrieved": "2026-07-06", "sourceType": "calculator", "confirmed": false, "weak": true, "paywalled": false, "placeholder": false, "note": "Recycled newspaper cellulose (blown). CORRECTED 2026-07-07: the cited GreenSpec page states k=0.040 (0.035 contradicted its own source). CIUR TDS has quoted 0.038 — confirm current TDS at sign-off. | Rob 2026-07-08: 0.038." }, { "kind": "product", "name": "Weber webertherm XM EWI EPS (white)", "manufacturer": "Weber", "category": "insulation", "subtype": "EPS", "lambda": 0.038, "thickness_mm": 100, "source": "https://www.uk.weber/files/gb/2019-02/weberthem%20XM%20and%20XP%20NSAI%20Certificate%20IAB%2009-0338_1.pdf?cb=493f2406", "sourceUrl": "https://www.uk.weber/files/gb/2019-02/weberthem%20XM%20and%20XP%20NSAI%20Certificate%20IAB%2009-0338_1.pdf?cb=493f2406", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "NSAI Agrément IAB 09/0338 (webertherm XM/XP), hosted on uk.weber: standard white EPS 'thermal conductivity 0.038 W/mK, density 15 kg/m3, 30 to 200 mm'. The current BBA PS1/PS2 cover only the grey board; white EPS is still offered on uk.weber." }, { "kind": "product", "name": "Weber webertherm XM EWI EPS 70 grey (032)", "manufacturer": "Weber", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://www.uk.weber/files/gb/2025-04/webertherm%20XM%20-%20BBA%20Certificate%20PS1%20%28Low%20rise%2C%20mechanically%20fixed%20EPS%29.pdf?cb=df292a12", "sourceUrl": "https://www.uk.weber/files/gb/2025-04/webertherm%20XM%20-%20BBA%20Certificate%20PS1%20%28Low%20rise%2C%20mechanically%20fixed%20EPS%29.pdf?cb=df292a12", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 91/2691 PS1 (2025 issue): 'webertherm EPS 70 grey (032) 30 to 200 mm, thermal conductivity 0.032 W/mK'. Graphite-enhanced EPS 70E to BS EN 13163, 1200 × 600, nominal density 15 kg/m³, 70 kPa. Same board in PS2 (adhesively fixed). Weber's older NSAI cert listed graphite EPS at 0.030 — the current BBA value is used." }, { "kind": "product", "name": "Weber webertherm XM EWI MFD mineral wool (dual density)", "manufacturer": "Weber", "category": "insulation", "subtype": "mineral_wool", "lambda": 0.036, "thickness_mm": 100, "source": "https://www.uk.weber/files/gb/2020-12/webertherm%20XM%20-%20PS5.pdf", "sourceUrl": "https://www.uk.weber/files/gb/2020-12/webertherm%20XM%20-%20PS5.pdf", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 91/2691 PS5: webertherm MFD (mineral fibre dual-density) slabs, 'declared thermal conductivity (λD) value of 0.036 W/mK', 1200 × 600, 50–200 mm, average density 110 kg/m³, BS EN 13162. Non-combustible." }, { "kind": "product", "name": "Wetherby Epsitherm 70E EWI EPS (grey)", "manufacturer": "Wetherby Building Systems", "category": "insulation", "subtype": "EPS", "lambda": 0.032, "thickness_mm": 100, "source": "https://docs.derby.gov.uk/padocumentserver/DownloadDocument.aspx?docid=203695482", "sourceUrl": "https://docs.derby.gov.uk/padocumentserver/DownloadDocument.aspx?docid=203695482", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 09/4625 (Wetherby EWI system): 'Wetherby Epsitherm 70E' grey enhanced EPS 70, Class E to BS EN 13163:2012, λD 0.032 W/mK, nominal density 15 kg/m³, 40–240 mm. Source is a planning-portal copy of the BBA certificate — Wetherby's own copies at wall-systems.co.uk returned 401 to the fetcher." }, { "kind": "product", "name": "Wetherby Epsitherm 90E EWI EPS (grey)", "manufacturer": "Wetherby Building Systems", "category": "insulation", "subtype": "EPS", "lambda": 0.03, "thickness_mm": 100, "source": "https://docs.derby.gov.uk/padocumentserver/DownloadDocument.aspx?docid=203695482", "sourceUrl": "https://docs.derby.gov.uk/padocumentserver/DownloadDocument.aspx?docid=203695482", "retrieved": "2026-09-16", "sourceType": "certificate", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "BBA 09/4625: 'Wetherby Epsitherm 90E' grey enhanced EPS 90, Class E to BS EN 13163:2012, λD 0.030 W/mK, nominal density 19 kg/m³, 40–240 mm. Planning-portal copy of the BBA certificate (see 70E note)." }, { "kind": "product", "name": "Womersley's Insulating Lime Render (NHL2)", "manufacturer": "Womersley's", "category": "finish", "subtype": "insulating_lime", "lambda": 0.12, "thickness_mm": 40, "source": "https://www.womersleys.co.uk/Guides/womersleys%20insulating%20plaster.pdf", "sourceUrl": "https://www.womersleys.co.uk/Guides/womersleys%20insulating%20plaster.pdf", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Measured K 0.12" }, { "kind": "product", "name": "Wood wool board (Heraklith)", "manufacturer": "Knauf (Heraklith)", "category": "finish", "subtype": "wood_fibre", "lambda": 0.085, "thickness_mm": 25, "source": "https://www.knaufinsulation.com", "sourceUrl": "https://www.knaufinsulation.com", "retrieved": "2026-07-06", "sourceType": "manufacturer", "confirmed": true, "weak": false, "paywalled": false, "placeholder": false, "note": "Mineral-bonded wood wool slab, range 0.07-0.10" }, { "kind": "product", "name": "Zinc", "manufacturer": "BS EN ISO 10456:2007 Table 3", "category": "metal", "subtype": "metal", "lambda": 110, "thickness_mm": 1, "source": "BS EN ISO 10456:2007 Table 3", "sourceUrl": null, "retrieved": "2026-07-06", "sourceType": "standard", "confirmed": false, "weak": false, "paywalled": true, "placeholder": false, "note": "Design value 110 W/mK" } ]