Every EPC band is shorthand for a number: the SAP score, a 1 to 100+ index of how cheap a building is to run for heating, hot water and lighting under standard assumptions GOV.UK SAP. Higher is better. The bands slice that scale into the seven chevrons on the certificate.
| Band | SAP score | In practice |
|---|---|---|
| A | 92+ | The top of the scale |
| B | 81-91 | New-build territory |
| C | 69-80 | The 2030 letting floor |
| D | 55-68 | Where the average home sits |
| E | 39-54 | Today's letting floor |
| F | 21-38 | Unlettable without exemption |
| G | 1-20 | The bottom of the scale |
Current versus potential rating
The certificate shows two positions on the scale. The current rating is the house as surveyed. The potential rating is the house if you carried out every recommendation listed on the certificate. The gap between them is deliberate: it tells a buyer or landlord how much headroom the building has, and roughly what work buys it.
The two charts on older certificates
Certificates issued in past years carried two A to G charts: energy efficiency (running cost) and environmental impact (CO2). The energy efficiency rating is the one every rule hangs on; the environmental impact rating never acquired legal force for domestic lets. If your old certificate shows different letters on the two charts, the efficiency one is the letter that matters. The reformed certificate will replace this single-headline design with four metrics.
Where the housing stock sits
The centre of gravity is the C/D boundary. The average English dwelling scores 67 EHS 2023-24, two points into band D. 52% of dwellings now reach C or above, and band C is the most common single band for both owner-occupied and privately rented homes at 45% of each EHS 2023-24. The old bands E to G have shrunk to 9% of the stock combined EHS 2023-24.
Which bands the law cares about
- E is the current floor for letting a domestic property in England and Wales GOV.UK MEES. Below it, you need an exemption.
- C is the confirmed floor for privately rented homes from 1 October 2030 Gov response Jan 2026.
- Selling has no minimum band at all; you just need a valid certificate.
For your own band's verdict, use the Can I let it? checker, or jump to band C, band D or band E, where most readers live. The methodology behind the scores is on EPC vs SAP, and the improvement guide covers moving up the scale.