EPC D to C — how many points do you actually need?
Between 1 and 14. Band D spans SAP scores 55–68 and band C begins at 69, so the only number that matters is the one printed on your current certificate. Here is how the scoring works and how to use it.
The band boundaries
| Band | SAP score | Where the housing stock sits |
|---|---|---|
| A | 92+ | Rare — typically new builds with solar |
| B | 81–91 | Most post-2010 new builds |
| C | 69–80 | The target — and the proposed rental floor |
| D | 55–68 | The largest single band in England's stock |
| E | 39–54 | Current legal minimum for rentals |
| F–G | 1–38 | Unlettable without a registered exemption |
What the score actually measures
SAP — the Standard Assessment Procedure — models the estimated cost of heating, lighting and hot water for your home per square metre, under standard occupancy. Existing homes are assessed with the reduced-data version, RdSAP: the assessor surveys what is physically there (wall type, insulation, glazing, heating system, controls) and the methodology fills standardised assumptions for the rest. Cheaper-to-run homes score higher. That is why a measure's point value tracks its effect on modelled running cost, not its visual impressiveness — and why gas heating, low-energy lighting and insulation punch above their weight while appliances and decor count for nothing.
A worked count
Take a 1965 semi-detached scoring D 61. The gap to C is 69 − 61 = 8 points. Its certificate recommends: cavity wall insulation (typical gain 5–10), loft top-up (1–3), heating controls (2–4). Any two of those three close the gap; all three give comfortable headroom. Compare that with a home at D 67 — two points short — where £250 of lighting and a cylinder jacket might finish the job. Same band, completely different project. The cost ladder prices both.
What RdSAP 10 changed
RdSAP 10, in force for assessments since mid-2025, was the biggest update to the methodology in a decade. For a D-to-C project, four changes matter:
- Windows are measured, not assumed. Assessors now record actual window dimensions and ages rather than applying a standard glazing fraction — homes with unusually large or small glazed areas can shift either way.
- Evidence rules are stricter. Insulation that cannot be seen needs documentary proof — installation certificates, invoices, building control sign-off or dated photos. No evidence can mean no points.
- More items are recorded in detail — ventilation, heating controls, photovoltaics and battery storage among them — so good kit that an older assessment glossed over now earns properly.
- Scores moved. Revised assumptions re-rated parts of the stock in both directions. If your certificate pre-dates 2025, your true starting point may differ from the number on it; a home that was 67 may already be a C, or a 56 may now be a 53.
Wider EPC reform — replacing the single cost-based score with multiple metrics — has been consulted on and is expected to change what certificates look like later this decade. Until it lands, SAP points remain the currency, and the points-per-pound ranking remains the strategy.
Finding your number
Your SAP score is on page one of your EPC, and every lodged certificate in England and Wales is free to view on the government's EPC register (find-energy-certificate.service.gov.uk). Check the lodgement date too: certificates last ten years, and one from 2017 describes a methodology two generations old. Once you have the score, counting is arithmetic — and preparing the evidence file is what turns spent money into recorded points.