This one is for our Scottish readers first — but anyone tracking where UK new-build standards and the Home Energy Model are heading should take a look. On 24 July 2026 the Scottish Government published its Stage 2 consultation on the next revision to Scotland’s energy standards, part of its work to introduce a ‘Passivhaus equivalent’ standard for new homes through the Building Standards. The most immediate headline is a slipped timetable; the more interesting detail is what’s proposed underneath.
The date has moved: autumn 2029, not 2028
The earlier Stage 1 partial response pointed to the new standards coming into force on 31 March 2028. That’s now moved. After reviewing the programme and the time needed to develop the supporting guidance, assessment methodologies and software, the Scottish Government intends to publish guidance and approved methodologies for Standard 6.1 in autumn 2027, with the new requirements now expected to take effect in autumn 2029.
It’s also keeping its options open on how the standard lands — whether in full, in phases, or as a voluntary route before it becomes mandatory.
Three options for the energy uplift
The consultation sets out three routes for future energy performance:
- Good Practice — roughly a 6% cut in carbon emissions against the current 2023 standards. Improved fabric, typically with an air source heat pump; PV required where an alternative heating system (such as direct electric or a heat network) is used.
- Best Practice — roughly a 37% cut in carbon emissions. A bigger step up in fabric performance plus mechanical ventilation with heat recovery (MVHR), and PV alongside a heat pump.
- Current Standard — retain the existing 2023 requirements, with no uplift.
Both of the uplift options strengthen the fabric; the Best Practice route is the more demanding, bringing in MVHR and, with a heat pump, PV.
New metrics and a HEM-based method
Compliance would be judged on two metrics: a Delivered Energy Rate (energy delivered to the home, excluding unregulated use and grid exports) and a Space Heat Demand Rate (driven by fabric performance — insulation, thermal bridging and airtightness). If that second metric sounds familiar, it should: it puts fabric and junction detailing right at the heart of compliance.
On calculation, Standard 6.1 will be based on the Home Energy Model with a Scottish wrapper — the same underlying engine England is moving towards, tailored for Scotland. A modified version of the Passivhaus Planning Package (PHPP) is also proposed as an approved compliance methodology. The current SAP 10.2 notional-dwelling approach to setting targets would be replaced with a series of target performance tables, selected by the home’s location, dwelling type, orientation and heating system.
Fabric and overheating
The maximum backstop U-values in Standard 6.2 would stay unchanged, but a new maximum air permeability of 5 m³/(h·m²) at 50 Pa would be introduced — so every new home would need an airtightness test at or below that level. On overheating, the Government is reviewing Standard 3.28 and considering whether PHPP could be used to assess overheating risk, with updated guidance to follow.
Why it’s worth reading in England too
Scotland and England run separate Building Standards, so none of this applies to an English Part L job. But the direction of travel is shared — HEM as the calculation engine, fabric-led metrics, tighter airtightness and a hard look at thermal bridging — and Scotland is arguably setting out its stall in more detail. If you work across the border, or you want a preview of the arguments likely to shape future English uplifts, it’s a useful read. The consultation closes on 16 October 2026.
Whichever standard you’re working to, the common thread is fabric: tighter airtightness targets and a fabric-driven space-heat metric both reward getting the junctions and PSI-values right at design stage. If you’d like your thermal bridging and fabric performance modelled properly — in Scotland or England — get in touch and we’ll tell you how we’d approach it.
Sources: Scottish building regulations: proposed changes to energy and environmental standards — Stage 2 consultation, gov.scot · Stage 2 consultation (consult.gov.scot) · Elmhurst Energy: Scottish Government outlines revised timeline in Stage 2 building regulations consultation