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. Grab a brew; we’ll keep this human.
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.