Last week, the UK Government (representing England and Wales), and the Scottish Government both released statements saying EPCs will remain unchanged until late 2027. To recap, the way Energy Performance Certificates look, how results are graded, and the way they are calculated, are all changing. When it happens, it will be the biggest refresh to EPCs since their creation in 2008.

A fresh set of Home Energy Model User Guides have been published - this will be particularly useful for manufacturers of domestic heating, cooling, hot water, ventilation and renewable systems.

The Senedd has published its response to last year's Approved Document Part L consultation, confirming new energy standards for building sites from 2027. Strictly speaking, FHS doesn't apply in Wales, but this news broadly follows what we're expecting from the UK Government in the coming weeks.

The UK Government has set out plans to replace rdSAP10 assessments with the Home Energy Model. Domestic Energy Assessors (DEA) are still getting to grips with rdSAP10 (which was only implemented back in the summer) following years of delays. This consultation also considers how the new EPC metrics will be defined. You’ve got until March 18th, 2026 to have your say.

EPC certificates in England and Wales will be changing from October 2026. There will still be an A-G rating. But the single rating is being replaced with a dashboard of information, primarily focusing on fabric performance.

The Scottish Government has outlined plans to update Technical Handbook Section 6 to scrap SAP and further tighten fabric performance standards. They're calling it a 'PassivHaus equivalent standard'. Specific details and timeframes will be confirmed later this year, with the final ‘Go Live’ date already confirmed as 31st March 2028.

When a SAP calculation spits out unexpected results, the assessor can look through the worksheets and, 99% of the time, they can find the reason and fix it. The Home Energy Model doesn’t produce simple worksheets that assessors can scrutinise, and it doesn’t have a single methodology you can thumb through. So how will we troubleshoot in HEM?

The Government's standard response about the release of the Future Homes Standard has changed recently from 'Autumn 2025' to 'in the coming months'.

This is only going to be exciting for us high-level Home Energy Model nerds, but new Home Energy Model Technical Documents have just been published on the DESNZ website. These docs explain the logic behind HEM.. a bit like the SAP methodology manual.

The Scottish Government has published what EPC Reform is going to look like. SAP assessors are advised to strap in… it could be a bumpy ride! Every EPC in Scotland will need to be redone, using a more complicated assessment tool that isn’t ready yet, with a nation of re-trained SAP assessors attending training courses that haven’t been written yet, signing up to 'new enhanced accreditation scheme requirements' that don’t exist yet.

When the FHS consultation was released in December 2023, there were two other consultations hidden in its shadow. This week's publication is the official response to one of those lesser-spotted policy proposals. In a nutshell, it confirms SAP is definitely going to be retired. HEM will take over as the method for complying with Approved Document Part L. It will also be used for calculating Energy Performance Certificates.

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 2025 to respond.

When an overheating assessor builds a 3D model of a development, they apply a Weather File to simulate a years’ worth of sunlight, wind and humidity. This climate data interacts with the building’s solar gains, air flow and thermal mass to calculate hourly internal temperatures, which ultimately gives us a Pass or a Fail for Approved Document Part O and TM59 assessments. CIBSE has recently published new weather files, based on more recent weather patterns and latest data.

When Part L changes next year, there will be two routes to compliance - using SAP10.3, or the new Home Energy Model. This allows HEM a chance to bed in, and means industry can continue using the familiar SAP tools for a while longer.

Over the years, the performance of PV panels drops. From my own experience, generation can reduce very quickly unless panels are cleaned.

The Future Homes Standard is a UK Government policy that’s reshaping how we design new homes so they’re far more energy efficient.

The proposed new Home Energy Model is expected to be published by the UK Government mid-2025. There's already plenty of anxiety about how mu

The construction industry is keen to plan ahead. With major changes on the way for Approved Document Part L, there's a growing appetite betw