Completely free — choose Non-domestic under the verdict and the tables switch.
Opens on a wall with the England Volume 2 tables selected. Switch to Wales or Scotland at any time.
England — Approved Document L Volume 2 (2021, incorporating 2023 amendments)
| Element | Table 4.1 limit — new buildings and new elements in existing buildings | Table 4.2 retained — threshold → improved |
|---|---|---|
| Flat roof | 0.18 | 0.35 → 0.18 |
| Pitched roof, insulation at rafter | 0.16 | 0.35 → 0.18 |
| Pitched roof, insulation at ceiling | 0.16 | 0.35 → 0.16 |
| Wall | 0.26 | 0.70 → 0.55 cavity fill / 0.30 external or internal insulation |
| Floor | 0.18 | 0.70 → 0.25 |
| Swimming pool basin | 0.25 | — |
| Windows, roof windows, curtain walling | 1.6 (windows in buildings similar to dwellings: 1.6 or WER band B) | — |
| Rooflights | 2.2 | — |
| Pedestrian doors (including glazed) | 1.6 | — |
| Vehicle access and similar large doors | 1.3 | — |
| High-usage entrance doors / roof ventilators | 3.0 | — |
All values W/m²K, area-weighted. Source: Approved Document L, Conservation of fuel and power, Volume 2: Buildings other than dwellings, 2021 edition incorporating 2023 amendments — Table 4.1 p.25, Table 4.2 p.27, paragraphs 4.5 and 4.7. Air permeability for new buildings 8.0 m³/(h·m²) at 50 Pa.
Wales and Scotland
| Element | Wales Vol 2 — new buildings | Wales Vol 2 — new element, existing building | Scotland Table 6.3 — all new work |
|---|---|---|---|
| Flat roof / pitched at rafter | 0.2 | 0.18 | 0.16 |
| Pitched roof at ceiling | 0.2 | 0.15 | 0.16 |
| Wall | 0.26 | 0.26 | 0.21 |
| Floor | 0.22 | 0.22 | 0.18 |
| Windows | 1.6 | 1.8 | 1.6 |
| Rooflights | 2.2 | 2.2 | 2.2 |
| Pedestrian doors | 1.8 | 1.8 | 1.4 |
| Retained elements | Table 4.2: 0.35 → 0.16 / 0.18 roofs; 0.70 → 0.55 / 0.30 walls; 0.70 → 0.25 floors | Individual areas and reconstruction: 0.70 walls and floors, 0.35 roofs; Table 6.3 as the benchmark | |
Sources: Approved Document L Volume 2, 2022 edition for use in Wales (takes effect 29 March 2023), Table 4.1 pp.36–37 and Table 4.2 p.40 — the tighter "essentially domestic in character" column (0.15 / 0.21 / 0.18) applies to student accommodation, care homes and similar; Building Standards Technical Handbook: Non-domestic, January 2025 edition, clause 6.2.1 Table 6.3 p.476 and clause 6.2.9.
Three things that go wrong on non-domestic reports
First, the dwellings table gets used. A 0.20 W/m²K wall is an amber "passes the limit, not the notional" result on Volume 1 and a clean pass on Volume 2, and a warehouse assessed against 0.18 floors and 0.11 roofs has been given the wrong test. Second, the retained-element table is cited as Table 4.3 — that is the Volume 1 number; in Volume 2 it is Table 4.2, and Volume 2's Table 4.3 is reference glazing systems. Third, the roof split is missed: for a retained roof the improved value is 0.16 only at ceiling level; rafter-level and flat roofs are 0.18. U-Monkey carries all three distinctions in its data and prints the table it used on the report.
How U-Monkey applies it
Choose Non-domestic and the nation under the verdict. New build is judged against the Table 4.1 (or 6.3) backstop with a note that BER ≤ TER is the real test; a new element in an existing building against the same table; an existing element as built against the 0.70 / 0.35 threshold; a renovated element against the improved value for its construction. Wall ties and EWI fixings through the insulation, air gaps and inverted roofs are corrected per BS EN ISO 6946 Annex F and itemised on the PDF.
Frequently asked questions
What U-values apply to a commercial building in England?
Approved Document L Volume 2 (2021 edition incorporating 2023 amendments) Table 4.1: flat roofs 0.18, pitched roofs 0.16, walls 0.26, floors 0.18, windows, curtain walling and pedestrian doors 1.6, rooflights 2.2, vehicle access doors 1.3, high-usage entrance doors 3.0 W/m²K. The same table covers new buildings and new or replacement elements in existing buildings (paragraph 4.5).
Is there a notional value for non-domestic elements, like the dwellings tables have?
Not in the Approved Document. Compliance for a new non-domestic building is a whole-building calculation — BER ≤ TER in SBEM or dynamic simulation — against a notional building whose fabric is defined in the NCM Modelling Guide, not as per-element targets. Table 4.1 is the worst-acceptable backstop, so meeting it is necessary but not sufficient. U-Monkey therefore shows only the backstop for non-domestic new build and says so.
What are the renovation thresholds for existing non-domestic elements?
Table 4.2 (England Vol 2, p.27; the identically numbered Welsh table): an element is a thermal element to be upgraded if it is worse than 0.70 (walls, floors) or 0.35 (roofs), and the improved target is then 0.55 for a cavity-filled wall, 0.30 for external or internal wall insulation, 0.25 for floors, 0.16 for a pitched roof insulated at ceiling level and 0.18 for a pitched roof insulated at the rafters or a flat roof. Note the rafter and flat-roof figures are 0.18, not the 0.16 that the dwellings table uses for every roof.
Which table is the retained-element table in Volume 2?
Table 4.2. In Volume 1 (dwellings) it is Table 4.3, and Volume 2’s Table 4.3 is a table of reference glazing systems for the solar-gain check — an easy citation to get wrong on a report. U-Monkey names the right table for the regime you choose.
Do Wales and Scotland have different non-domestic figures?
Yes. Wales (Volume 2, 2022): new buildings roofs 0.2, walls 0.26, floors 0.22, windows 1.6, roof windows and curtain walling 1.8, doors 1.8; new elements in existing buildings 0.18 roofs (0.15 at ceiling level), 0.26 walls, 0.22 floors, or a tighter column where the building is essentially domestic in character. Scotland (Non-domestic Technical Handbook, January 2025, Table 6.3): walls 0.21, floors 0.18, roofs 0.16, windows 1.6, rooflights 2.2, pedestrian doors 1.4, one table for new work, extensions and reconstructed elements.
Dwellings: England · Wales · Scotland. Full tutorial: how to use U-Monkey.