Air-source heat pumps extract heat from outdoor air at 250–400% efficiency. The BUS provides £7,500 toward installation — £9,000 for off-gas-grid properties. No EPC required since April 2026.
An air-source heat pump (ASHP) works like a refrigerator in reverse — extracting heat from outdoor air (even in cold temperatures) and concentrating it to heat your home and hot water at 250–400% efficiency. For every 1 unit of electricity used, a heat pump delivers 2.5–4 units of heat.
| Property | System size | Installed cost | After £7,500 BUS |
|---|---|---|---|
| 2–3 bed house | 6–8 kW | £8,000–£11,000 | £500–£3,500 |
| 3–4 bed house | 8–12 kW | £10,000–£14,000 | £2,500–£6,500 |
| Off-gas-grid property | 8–12 kW | £10,000–£14,000 | From £1,000 (£9,000 BUS) |
No EPC required since April 2026: BUS applications no longer require a valid EPC. The old insulation recommendation rule has been removed.
No, since 28 April 2026. BUS applications no longer require a valid EPC.
On a standard tariff (~28p/kWh), costs can exceed gas. On a specialist heat pump tariff (7–15p/kWh overnight), running costs are comparable or lower.
Usually no — most fall under permitted development in England, Scotland and Wales. Listed buildings and conservation areas may need consent.