The Energy Performance Certificate has looked more or less the same for years: one coloured dial, one A–G band, one number that’s meant to sum up a whole building. That’s about to change. The government has confirmed a wholesale reform of the domestic EPC — a move from a single headline rating to four separate metrics, produced by the Home Energy Model (HEM) rather than RdSAP.
What’s actually changing
In its partial response to the Energy Performance of Buildings consultation (updated 9 March 2026), the Ministry of Housing, Communities and Local Government confirmed that domestic EPCs will replace the current single cost-based headline with four headline metrics (GOV.UK, partial government response):
- Energy cost — an estimate of running costs, the nearest thing to today’s headline.
- Fabric performance — a measure of the building envelope that doesn’t move with energy prices; effectively a proxy for how well a home holds its heat.
- Heating system — a rating reflecting the efficiency and carbon intensity of the heat source, rewarding a move to low-carbon heating.
- Smart readiness — how well the home can work with smart meters and flexible tariffs.
Sitting behind those, the certificate will also carry a secondary energy demand figure (based on delivered energy) and a secondary carbon metric. To keep comparisons possible during the switchover, the legacy Energy Efficiency Rating stays on the certificate for now. Non-domestic EPCs are treated differently: they keep the single carbon-based Environmental Impact Rating as their headline.
The thinking is straightforward. One number was always doing too much work — a cost metric penalises electric heating on price, blurs fabric quality, and shifts with the energy market. Splitting it out gives owners a clearer, fabric-first picture: insulate well, then electrify.
The bit that matters to assessors: HEM produces it
This isn’t just a redesign of the certificate. Reformed domestic EPCs are intended to be generated using the Home Energy Model, through a separate DESNZ consultation on how new-style EPCs will be produced and how the four metrics will be banded. For existing homes, that points to a more modular approach to assessment than the RdSAP data set you use today.
If you’ve been watching HEM purely as the SAP replacement for new-build compliance, this is the other half of the story — HEM is also the engine intended to sit under the domestic EPC. The current RdSAP-based system remains the only route for existing-dwelling EPCs until the reformed methodology goes live.
When
Originally the government wanted new-style EPCs from October 2026. On 9 March 2026 that was pushed back: the launch now moves to the second half of 2027, with government committing to agree a specific date and a shared implementation plan with industry and the devolved administrations by summer 2026. So the plan itself is due about now — worth keeping an eye on. A final consultation response, covering the remaining questions (EPC data, EPC quality, DEC validity periods and more), is still expected during 2026.
A few other changes worth banking
Alongside the metrics, the response confirmed some practical points that will land on assessors and agents:
- The 10-year validity period is retained for both existing and reformed EPCs.
- An EPC will be required at the point of marketing a property, not up to 28 days after — so the certificate needs to be in hand before a home goes on the market.
- Scope widens: a valid EPC for the whole HMO when a single room is let, EPCs for short-term lets regardless of who pays the bills, and the heritage exemption removed.
And the deadline that gives all this its edge hasn’t moved: the private-rented MEES EPC C by 2030 target still stands, which compresses the window between the new methodology arriving and landlords having to meet it.
What to do now
Nothing changes on your current EPCs today — anything issued now stays valid for ten years, well past 2030. But the direction is set: a four-metric certificate, produced by HEM, with fabric performance pulled out as a headline in its own right. If you assess existing homes, this summer’s implementation plan is the one to watch, and it’s a good moment to get comfortable with HEM’s approach before the retraining rush.
We’ll keep tracking the reform as the implementation plan and final response land. If you’d like the plain-English version of each step as it happens — and a heads-up on what it means for your assessments — keep an eye on the Energycount news feed.