EPC Ratings and Heat Pumps - What You Need to Know
Your Energy Performance Certificate (EPC) matters for heat pump eligibility and performance. Here is what the ratings mean, what you need for the BUS grant, and how to improve yours.
What is an EPC?
An Energy Performance Certificate (EPC) rates a property's energy efficiency from A (most efficient) to G (least efficient). It is produced by an accredited domestic energy assessor following a survey of the property. EPCs are required when a property is sold or let, and are valid for 10 years.
For heat pumps, the EPC matters for two reasons: it is required for the BUS grant (you must have a valid EPC issued in the past 10 years), and it gives an indication of how suitable the property is for a heat pump — though it is not the whole picture.
Do you need a specific EPC rating for the BUS grant?
No. Unlike some earlier grant schemes, the current BUS (Boiler Upgrade Scheme) does not require a minimum EPC rating. You simply need a valid EPC issued within the last 10 years. Even a G-rated property can be eligible — though a heat pump installation in such a property is likely to have higher running costs until the fabric is improved.
The one exception: if your EPC has a recommendation to install loft or cavity wall insulation, you must have that insulation in place (or have a valid reason for not installing it) before the BUS voucher will be issued. This rule exists to prevent heat pumps being installed in homes that could easily be improved first.
EPC ratings and heat pump suitability
| Rating | Score | Heat pump | BUS | Notes |
|---|---|---|---|---|
| A | 92-100 | Excellent | Very rare in UK housing stock. Heat pump will perform optimally. | |
| B | 81-91 | Excellent | Well-insulated property. Heat pump is a strong choice. | |
| C | 69-80 | Good | Most UK homes. Heat pump works well, may benefit from minor improvements. | |
| D | 55-68 | Possible | The most common UK EPC rating. Heat pump can work but insulation improvements are strongly recommended. | |
| E | 39-54 | Caution | Heat pump can still be installed but heat loss will be higher and running costs elevated until insulation is improved. | |
| F | 21-38 | Caution | BUS grant still available, but MCS installers may recommend significant insulation upgrades before or alongside installation. | |
| G | 1-20 | Specialist only | Technically eligible for BUS, but heat pump installation without major fabric improvements is not recommended. |
How to get an EPC
EPCs must be produced by an accredited domestic energy assessor. You can find one at the government's official assessor register. Cost is typically £60-120. The assessor will visit your property for 30-60 minutes, assess insulation, heating systems, windows, and lighting, then produce the certificate.
Before the assessor visits, check if your property already has a valid EPC on the government's EPC register at epcregister.com — it is free to check and you may find a valid certificate already exists from a previous sale or letting.
Improving your EPC before a heat pump installation
Improving insulation before a heat pump installation has a double benefit: it improves your EPC rating, and it reduces the heat loss from your property — meaning you may need a smaller (and cheaper) heat pump, and your running costs will be lower year-round.
Most cost-effective insulation improvements
| Improvement | Typical cost | EPC impact |
|---|---|---|
1Loft insulation (if absent) | £300-600 | +5-15 points |
2Cavity wall insulation | £600-1,500 | +4-10 points |
3Double glazing (replace single) | £3,000-8,000 | +3-8 points |
4Floor insulation (suspended timber) | £800-2,000 | +2-6 points |
5Draught proofing | £100-300 | +1-3 points |
6Upgrade heating controls | £200-600 | +1-4 points |
EPC impact varies significantly by property. Costs as of April 2026.
Important disclaimer
heatpumpcompared.co.uk is editorially independent and not affiliated with any heat pump manufacturer or installer. We do not provide heating advice. Prices, specifications, SCOP ratings and grant amounts are correct as of April 2026 but are subject to change. Always commission a professional heat loss survey before purchasing a heat pump system.