Heat pump costs vary significantly based on property size, existing system, and chosen installer. Here's a transparent breakdown of what to expect in 2025.
Air source heat pump supply and installation costs (before grant)
- Small property (1–2 bed): £7,000–£10,000
- Average 3-bed semi: £10,000–£14,000
- Larger 4-bed detached: £13,000–£18,000
What affects the cost
Radiator upgrades: If existing radiators are undersized for heat pump temperatures, upgrades add £1,500–£4,000. Cylinder upgrade: Heat pumps require a larger cylinder (usually 200–250 litres) — add £600–£1,200. Electrical upgrades: Consumer unit or supply upgrades if needed — £500–£2,000. Property insulation: Required improvements before installation — variable.
After the £7,500 BUS grant
Most average 3-bed homes: £3,000–£7,500 after grant. Small well-insulated properties: sometimes under £3,000 after grant — comparable to a premium gas boiler installation.
Running cost comparison
Gas (7p/kWh, 94% efficient): ~7.4p/kWh heat. Heat pump (28p/kWh electricity, COP 3.0): ~9.3p/kWh heat. Gas currently slightly cheaper to run for most homes — but the gap narrows as electricity becomes greener.
Are you eligible for the BUS grant?
We handle BUS applications on your behalf. Contact us to check your eligibility and get a heat pump assessment.