The Boiler Upgrade Scheme now offers £7,500 for an air-source or ground-source heat pump, and £2,500 for the new air-to-air option. Whether the maths works for your home depends on insulation, how cheap your current heating is, and your electricity rate. This calculator handles all of it.
Heat demand starts from typical UK figures by property type (detached ~14,000 kWh/yr, semi ~12,000, terrace ~10,000, flat ~6,000) and is adjusted for bedrooms and EPC rating. An EPC C home uses ~15% less heat than D; an F home uses ~30% more.
Heat pump electricity = heat demand ÷ SCOP. We assume SCOP 3.0 for ASHP, 4.0 for GSHP and 2.5 for air-to-air systems. Real-world SCOP depends on radiator sizing, hot water demand and your installer's setup quality.
Current cost uses 6.5p/kWh gas, 9p oil, 12p LPG. Override with your actual bill for a more accurate result.
Install costs: ASHP £10–14k typical, GSHP £18–25k (deeper bore + groundwork), air-to-air £4–7k. The Boiler Upgrade Scheme grant is deducted. We compare against the cost of replacing a like-for-like boiler (~£3,000) to give an honest "incremental" payback.
Estimates only. SCOP is highly installer-dependent and your savings hinge on getting the radiator sizing right. Get at least 3 quotes from MCS-certified installers.