Wales consults to change SAP, photo evidence and overheating regs

The Welsh Government has released a consultation looking to change Approved Documents Part L, Part O and Part F, following in the footsteps of the Future Homes Standard policy in England.

You've got until 17th November to respond. Documents can be found here... 

https://www.gov.wales/building-regulations-part-l-2025-review

I've had a read through the proposals, and a few suggestions have caught my eye... 👀 

Wales is following in the footsteps of England's Future Homes Standard policy, with a nod to Scotland's Passivhaus Principle consultation

☀️ There's a plan to extend the reach of Part O to require overheating calculations on loft conversions, and when glazing is replaced in existing blocks of flats.

💡 Wales is the only region in the UK to set a minimum EPC rating for all new dwellings. The proposal is to scrap this target, replacing it with an Energy Use Intensity (EUI) target.

📷 Photographic Evidence could be extended to cover newly built non-residential buildings. This is currently only required for dwellings.

💻 As expected, the Home Energy Model (HEM) will replace SAP for calculating compliance with the new Part L targets. A transitional stage using SAP10.3 hasn't been confirmed, but is mentioned as a backstop in case HEM isn't ready.

⚖️ For Part L compliance, there are two notional specifications. Both are similar to FHS, using heat pumps and PV to calculate targets. The stricter option also includes MVHR ventilation and a notional air test of 1.5. No decision yet on which option will be used. Gas boiler are not expected to comply with the new requirements.

🏘️ Large extensions will be expected to include PV panels. The consultation also discusses mandatory PV on new builds, similar to the UK Government's plan.

🏭 SBEM calculations will also need to take the low-carbon heating and PV route. There won't be any major changes to the current methodology, but the notional specification will be changed to lower energy and emission targets. 

⏳ Timescales are tight.. the consultation closes in November, and updated text to Part L, Part O and Part F should be confirmed in the first half of 2026. It will be ready for implementation before the end of 2026.

I'll dig deeper into some of these points in future posts.