Heat Pump Cost by House Type: What You Will Pay in 2026
The cost of an air source heat pump varies significantly by property type. A 2-bed flat costs around £7,000 to £10,000 installed, while a 4-bed detached runs £11,000 to £16,000. The £7,500 BUS grant applies to all property types, bringing the smallest installations down to under £500 out of pocket. This guide gives you the exact cost, heat pump size, and annual running cost for every common UK house type so you can budget accurately.
Cost summary by property type
| Property type | HP size (kW) | Installed cost | After BUS grant | Annual running cost |
|---|---|---|---|---|
| 1-2 bed flat | 4 to 6 | £7,000 to £10,000 | £0 to £2,500 | £440 to £580 |
| 2 bed terrace | 5 to 7 | £8,000 to £10,000 | £500 to £2,500 | £520 to £680 |
| 3 bed end-terrace | 7 to 9 | £9,000 to £11,000 | £1,500 to £3,500 | £620 to £820 |
| 3 bed semi-detached | 8 to 10 | £9,000 to £12,000 | £1,500 to £4,500 | £660 to £900 |
| 3 bed detached | 9 to 12 | £10,000 to £13,000 | £2,500 to £5,500 | £760 to £1,040 |
| 4 bed detached | 10 to 14 | £11,000 to £16,000 | £3,500 to £8,500 | £900 to £1,260 |
| 5 bed detached | 14 to 18 | £13,000 to £19,000 | £5,500 to £11,500 | £1,100 to £1,520 |
Installed cost includes heat pump unit, installation labour, commissioning, and MCS certificate. Does not include radiator upgrades (£2,000 to £4,000) or hot water cylinder (£800 to £1,500) if needed. Running costs assume COP 2.9, heat pump tariff at ~16p/kWh. Based on well-insulated properties.
Use our heat pump calculator for a personalised estimate based on your specific property, insulation level, and current heating system.
What is included in the installed cost?
The figures above cover the core heat pump system: the outdoor unit, indoor controls, refrigerant pipework connecting outdoor and indoor units, electrical connections, system commissioning, and the MCS certificate required for the BUS grant. This is the cost your MCS installer will quote for the heat pump itself.
Additional costs that may apply depending on your property:
| Additional item | Cost | When needed |
|---|---|---|
| Radiator upgrades | £2,000 to £4,000 | Most older homes with standard-sized radiators |
| Hot water cylinder | £800 to £1,500 | If replacing a combi boiler (no existing cylinder) |
| Underfloor heating (per floor) | £3,000 to £6,000 | Optional; works very efficiently with heat pumps |
| Pipework modifications | £500 to £1,500 | If existing pipework is incompatible |
| Concrete plinth for outdoor unit | £200 to £500 | Most installations require a base |
Radiator upgrades are the most common additional cost. Your MCS installer will assess whether your existing radiators are large enough to heat each room at the lower flow temperatures a heat pump operates at.
Detailed breakdown by house type
Flats
A flat typically needs the smallest heat pump (4 to 6 kW) due to shared walls reducing heat loss. The main challenge is not cost but logistics: where to put the outdoor unit. Ground-floor flats can place it in a garden or patio area. Top-floor flats may use a balcony. Mid-floor flats are the hardest to serve. You will need freeholder permission for any external installation.
Read our guide to heat pumps in flats for the full picture on permissions, noise considerations for neighbours, and alternative solutions.
After the £7,500 BUS grant, a flat heat pump installation can cost as little as £0 out of pocket for smaller systems. Running costs on a heat pump tariff are typically £440 to £580 per year.
Terraced houses
Terraced homes benefit from shared party walls, which reduce heat loss compared to detached properties. A 2-bed mid-terrace typically needs only a 5 to 7 kW heat pump. A 3-bed end-terrace, with one exposed side wall, needs 7 to 9 kW.
The outdoor unit is usually placed in the rear garden. In terraced streets with small gardens, noise can be a concern for neighbours. Modern heat pumps operate at 40 to 50 dB at one metre, which is acceptable at typical garden distances. Read our noise guide for practical tips on placement and reduction.
After the grant, a mid-terrace installation costs £500 to £2,500 out of pocket. An end-terrace costs £1,500 to £3,500.
Semi-detached houses
The 3-bed semi is the most common UK house type and the sweet spot for heat pump economics. One exposed side wall and a moderate floor area mean a manageable 8 to 10 kW system. The outdoor unit fits comfortably in a side or rear garden.
Total cost after the BUS grant is £1,500 to £4,500 for the heat pump, plus £2,000 to £4,000 for radiator upgrades if your existing radiators are undersized. Many semis built in the 1950s to 1980s already have generously sized radiators that work adequately with a heat pump.
Annual running costs on a heat pump tariff run £660 to £900, compared to £900 to £1,130 for gas. Read our running costs guide for the full comparison.
Detached houses
Detached homes have the highest heat loss due to four exposed walls and typically larger floor areas. A 3-bed detached needs 9 to 12 kW, a 4-bed needs 10 to 14 kW, and a large 5-bed may need 14 to 18 kW.
The good news: detached homes have the most flexibility for outdoor unit placement, fewer neighbour noise concerns, and often enough garden space for ground source heat pumps (which achieve better efficiency but cost £15,000 to £35,000 before the grant).
For older detached properties built before 1930 with solid walls, insulation is critical before sizing the heat pump. Read our heat pumps in old houses guide for the full preparation sequence.
Insulate first to reduce your heat pump cost
Better insulation means a smaller, cheaper heat pump. Loft insulation (£300 to £600) and cavity wall insulation (£400 to £1,500) can drop your required heat pump size by 2 to 4 kW, saving £1,000 to £3,000 on installation. If you qualify for ECO4, get free insulation first.
How insulation level affects cost
The figures in the main table assume a well-insulated property. If your home has poor insulation, the required heat pump size and cost increases significantly.
| Insulation level (3-bed semi) | Heat demand (kWh) | HP size needed | Installed cost |
|---|---|---|---|
| Well insulated (270mm loft, filled cavity, double glazed) | 12,000 | 8 to 10 kW | £9,000 to £12,000 |
| Partially insulated (100mm loft, filled cavity, mixed glazing) | 15,000 | 10 to 12 kW | £10,000 to £13,000 |
| Poorly insulated (minimal loft, unfilled cavity, single glazed) | 20,000 | 12 to 16 kW | £12,000 to £16,000 |
Upgrading from poorly to well insulated costs £1,000 to £3,000 but saves £3,000 to £4,000 on the heat pump and reduces running costs by 30 to 40% permanently.
Use our insulation savings calculator to see the return on insulating before installing a heat pump.
Ground source vs air source by house type
Ground source heat pumps achieve higher efficiency (COP 3.5 to 4.5 versus 2.6 to 3.2 for air source) but cost significantly more and require substantial outdoor space for boreholes or horizontal loops.
| Property type | Air source cost | Ground source cost | Ground source practical? |
|---|---|---|---|
| Flat | £7,000 to £10,000 | n/a | No (no garden access) |
| Terrace | £8,000 to £11,000 | £18,000 to £28,000 | Rarely (small gardens) |
| Semi-detached | £9,000 to £12,000 | £20,000 to £30,000 | Sometimes (needs 100m+ borehole or 200m2 garden) |
| Detached | £10,000 to £16,000 | £22,000 to £35,000 | Often (larger gardens) |
Both air source and ground source qualify for the £7,500 BUS grant. Ground source running costs are 15 to 25% lower than air source due to higher COP.
For most UK homes, air source is the practical and cost-effective choice. Ground source makes financial sense only for larger detached properties with adequate land where the higher efficiency offsets the much greater installation cost over 20+ years.
The BUS grant and total out-of-pocket cost
The Boiler Upgrade Scheme provides £7,500 towards any heat pump installation, regardless of property type. The grant is deducted from your installer's invoice. You pay only the balance.
Combined with 0% VAT (until March 2027) and potential ECO4 funding for insulation, the realistic out-of-pocket cost for a complete heat pump retrofit is:
| Property type | HP plus radiators plus cylinder | After BUS grant | After BUS plus 0% VAT |
|---|---|---|---|
| 2-bed terrace | £11,000 to £14,000 | £3,500 to £6,500 | £3,500 to £6,500 |
| 3-bed semi | £12,000 to £17,000 | £4,500 to £9,500 | £4,500 to £9,500 |
| 4-bed detached | £14,000 to £22,000 | £6,500 to £14,500 | £6,500 to £14,500 |
0% VAT applies automatically through VAT-registered installers until March 2027. Figures include radiator upgrades and hot water cylinder where needed.
Check all available funding with our grant eligibility checker.
Running costs by house type
Once installed, running costs depend on your heat demand and electricity tariff. Here is what each property type costs to heat per year with a heat pump versus gas.
| Property type | Gas boiler | HP (standard tariff) | HP (heat pump tariff) |
|---|---|---|---|
| 2-bed terrace | £601 | £676 | £441 |
| 3-bed semi | £901 | £1,014 | £662 |
| 3-bed detached | £1,127 | £1,267 | £828 |
| 4-bed detached | £1,352 | £1,521 | £993 |
Gas at 6.76p/kWh (90% efficiency). HP standard tariff at 24.5p/kWh (COP 2.9). HP tariff at ~16p/kWh effective. Ofgem Q1 2026 rates. Well-insulated properties.
Read our full heat pump running costs guide for detailed analysis including oil and LPG comparisons. Use the boiler vs heat pump calculator for your specific property.
To optimise your running costs, see recommended smart thermostats for heat pump scheduling and recommended energy monitors to track your actual consumption. For noise reduction on the outdoor unit, see recommended anti-vibration pads.
Frequently asked questions
How much does a heat pump cost for a 3-bed semi?
£9,000 to £12,000 installed, or £1,500 to £4,500 after the £7,500 BUS grant. Add £2,000 to £4,000 for radiator upgrades if needed. Use our calculator for your exact figure.
How much does a heat pump cost for a detached house?
£11,000 to £16,000 for a 4-bed detached, or £3,500 to £8,500 after the grant. Larger 5-bed properties cost £13,000 to £19,000. Insulating first reduces the required size and cost.
Can you install a heat pump in a flat?
Yes, with freeholder permission. Costs £7,000 to £10,000 before the grant. Read our heat pumps in flats guide for placement options and restrictions.
What size heat pump do I need?
2-bed terrace: 5 to 7 kW. 3-bed semi: 8 to 10 kW. 4-bed detached: 10 to 14 kW. An MCS installer calculates the exact size based on your property's heat loss. Better insulation means a smaller unit.
Are bigger heat pumps more expensive to run?
Not if correctly sized. Running costs depend on heat demand and electricity tariff, not unit size. A well-insulated 4-bed detached costs less to heat than a poorly insulated 3-bed semi.
Data sources
Cost data from Energy Saving Trust and MCS installer market data. Energy prices from Ofgem Q1 2026 price cap. BUS grant details from GOV.UK.