| Current EPC | Reformed EPC | |
|---|---|---|
| Headline | One A to G energy efficiency rating from a SAP score GOV.UK SAP | Four metrics: energy cost, fabric performance, heating system, smart readiness Partial response Jan 2026 |
| Calculation engine | SAP / RdSAP 10 | Home Energy Model outputs; an EER C on a current EPC lodged before 1 Oct 2029 still counts for the 2030 standard until it expires Gov response Jan 2026 |
| What MEES reads | The single EER band (E floor) | Fabric performance first, then heating system or smart readiness, for the 2030 C-equivalent standard Gov response Jan 2026 |
| Smart readiness | Invisible to the certificate | A headline metric |
| Arrival | In force now | Second half of 2027, moved from October 2026 on 9 March 2026 EPB consultation |
| Old certificates | Valid 10 years from lodgement | Existing EPCs retain their validity; no conversion, no voiding Partial response Jan 2026 |
Will old certificates convert?
No. The confirmed position is that certificates in force keep their 10-year validity as issued Partial response Jan 2026. The register will simply hold both vintages for years, the way it already holds RdSAP 9 and RdSAP 10 assessments side by side. A 2025 certificate remains usable for selling or letting until its printed expiry.
Before versus after: what to do differently
- Before the switchover: renew only with a reason (see the timing page); if improving a rental for 2030, weight fabric measures, because the new standard reads fabric first Gov response Jan 2026.
- After: expect your next certificate to say four things instead of one, and expect listings, lenders and MEES enforcement to reference the metric relevant to them rather than a single letter.
The reform's full story is on EPC reform, the engine on Home Energy Model, and what the current certificate shows on EPC ratings explained. Dates, as ever, live on the reform tracker.