Heat Pump Cost for a 4-Bedroom House: Full 2026 Breakdown
An air source heat pump for a 4-bed house costs £11,000 to £16,000 installed. The £7,500 Boiler Upgrade Scheme grant brings that down to £3,500 to £8,500, and homes replacing an oil or LPG boiler now get £9,000. Add radiator upgrades and a hot water cylinder and the realistic total is £6,500 to £14,500 after the grant. At the Ofgem price cap for October to December 2026, running costs are £1,117 a year on a heat pump tariff, £477 less than gas. This guide covers every cost that is specific to a 4-bed home: the prices people actually paid in 2026, sizing, the models installers fit, radiators and cylinders, running costs, and what to check in a quote.
In this guide
What a 4-bed heat pump really costs in 2026 Complete cost breakdown 4-bed semi versus 4-bed detached What size heat pump for a 4-bed house Which heat pumps suit a 4-bed house Radiators, cylinder and pipework Running costs: 4-bed detached The Boiler Upgrade Scheme for a 4-bed Is a heat pump worth it for a 4-bed house Ground source vs air source Getting quotes: what to check Frequently asked questionsWhat a 4-bed heat pump really costs in 2026
The most reliable price data comes from installations paid for through the Boiler Upgrade Scheme, which the Microgeneration Certification Scheme (MCS) publishes every quarter. For England and Wales in April to June 2026, the median air source heat pump installation cost £12,908. A quarter of installations came in under £11,128 and a quarter cost more than £15,627. These are prices actually paid on the invoice, not quotes.
| Position | Installed cost | After £7,500 grant | After £9,000 oil or LPG grant |
|---|---|---|---|
| Lower quartile | £11,128 | £3,628 | £2,128 |
| Median | £12,908 | £5,408 | £3,908 |
| Upper quartile | £15,627 | £8,127 | £6,627 |
MCS Data Dashboard, BUS-funded air source installations, England and Wales, April to June 2026. Excludes radiator and cylinder work invoiced separately.
A 4-bed house normally sits in the upper half of that range. It needs a 10 to 14 kW unit rather than the 5 to 8 kW that suits a terrace, it has more radiators to check and replace, and it usually needs a 250 to 300 litre hot water cylinder. Installers also spend longer on the design, because a larger house has more rooms to survey and more pipework to trace. That is why the realistic range for a 4-bed is £11,000 to £16,000 before the grant, with well-insulated 1990s and newer homes at the bottom and older, larger or poorly insulated ones at the top. Use our heat pump calculator for an estimate that reflects your own insulation level and heating fuel.
Complete cost breakdown
| Cost element | Range | Notes |
|---|---|---|
| Heat pump unit and installation | £11,000 to £16,000 | 10 to 14 kW air source. Includes unit, pipework, controls, MCS certificate |
| BUS grant | -£7,500 | Deducted from the installer invoice. £9,000 if you are replacing an oil or LPG boiler |
| Net heat pump cost | £3,500 to £8,500 | What you actually pay for the heat pump |
| Radiator upgrades | £3,000 to £5,500 | 4 to 7 radiators typically need upsizing. See radiator sizing guide |
| Hot water cylinder | £800 to £1,500 | Required if replacing a combi boiler, 250 to 300 litres for a 4-bed |
| Pipework modifications | £0 to £1,500 | If existing pipework is microbore or undersized |
| Concrete plinth | £200 to £500 | Base for the outdoor unit |
| Total out of pocket | £6,500 to £14,500 | After the BUS grant, including all ancillary costs |
0% VAT applies until March 2027. Costs from MCS installation data and Energy Saving Trust.
The heat pump itself is only part of the bill. On a 4-bed retrofit the radiator work, cylinder and pipework together add £4,000 to £8,500, so a quote that covers the heat pump alone is not the number to budget from. Ask every installer for an itemised quote that lists each radiator they intend to change.
Get heat pump quotes for your home
Tell us about your property to request quotes from MCS-certified installers covering your postcode. Free, no obligation, and nobody calls you unless you tick the box.
- MCS-certified installers only
- Grant of £7,500 handled by the installer
- No obligation, no spam
4-bed semi versus 4-bed detached
Not every 4-bed house is detached. A 4-bed semi shares one wall, so it loses less heat, needs a smaller unit and costs less to run. The difference is worth £1,000 to £3,000 on installation and around £250 a year on running costs.
| Property | Typical heat demand | Heat pump size | Installed cost | After £7,500 grant |
|---|---|---|---|---|
| 4-bed semi-detached | 13,000 to 15,000 kWh | 8 to 10 kW | £10,000 to £13,000 | £2,500 to £5,500 |
| 4-bed detached | 16,000 to 20,000 kWh | 10 to 14 kW | £11,000 to £16,000 | £3,500 to £8,500 |
Heat demand assumes loft insulation, double glazing and filled cavity walls where present.
At 14,000 kWh of heat demand, a 4-bed semi costs £1,240 a year on gas, £1,271 on a heat pump with a standard tariff, and £869 on a heat pump tariff at the October to December 2026 price cap. The detached figures are in the running costs section below. For the full picture on a semi, read our 3-bed semi heat pump cost guide.
What size heat pump for a 4-bed house
A 4-bed detached house typically needs a 10 to 14 kW air source heat pump. The exact size depends on your insulation level.
| Insulation level | Heat demand (kWh) | HP size | Installed cost |
|---|---|---|---|
| Well insulated (270mm loft, filled cavity, double glazed) | 14,000 to 16,000 | 10 to 12 kW | £11,000 to £13,000 |
| Partially insulated | 17,000 to 20,000 | 12 to 14 kW | £13,000 to £15,000 |
| Poorly insulated | 22,000 to 28,000 | 14 to 18 kW | £15,000 to £19,000 |
Insulating first reduces heat pump size and cost. See our loft insulation and cavity wall insulation guides.
Your MCS installer must carry out a room-by-room heat loss calculation before quoting. It works out how much heat each room loses on the coldest design day, usually around minus 3C in southern England and lower further north, and sizes the unit to cover the total with a small margin. As a rule of thumb, a reasonably insulated 4-bed needs 40 to 60 watts per square metre of floor area, so a 140 square metre house has 6 to 9 kW of heat loss and needs a 10 to 12 kW unit once hot water is included. Oversizing is not a safe default. A unit that is too big cycles on and off, wears faster and runs less efficiently than one sized to the house, so treat a quote with no heat loss calculation behind it as a warning sign.
Insulate first to save £2,000 to £4,000
Loft insulation (£300 to £600) and cavity wall insulation (£400 to £1,500) reduce your heat pump cost and running costs permanently. If you qualify for ECO4, get free insulation first.
Which heat pumps suit a 4-bed house
Installers fit the 10 to 14 kW class from four manufacturers more than any other. The table shows the models you are most likely to be quoted for a 4-bed house.
| Model | Outputs for a 4-bed | Refrigerant | Max flow temp | Why pick it |
|---|---|---|---|---|
| Vaillant aroTHERM plus | 10 kW, 12 kW | R290 | 75C | High flow temperature keeps more existing radiators, very quiet mode |
| Mitsubishi Ecodan | 11.2 kW, 14 kW | R32 or R290 by model | 60 to 70C | Largest UK installer base, Zubadan models hold output to minus 25C |
| Daikin Altherma 3 H HT | 14 kW, 16 kW, 18 kW | R32 | 70C | Widest cold-weather range, long track record |
| Samsung EHS Mono HT Quiet | 12 kW, 14 kW | R32 | 70C | Value option with high temperature output |
Outputs are the nominal ratings in each range that cover a 4-bed house. Your heat loss calculation decides which one you need.
Brand matters less than design. Ask for a design flow temperature of 50C or lower, a seasonal coefficient of performance (SCOP) above 3.5 in the quote, and an MCS 020 noise assessment for the outdoor unit position. R290 units such as the aroTHERM plus can run hotter, which sometimes means fewer radiator changes in an older house, while the Ecodan and Altherma ranges have the largest installed base and the widest parts availability. A well-designed system from any of these manufacturers will outperform a poorly designed one from the best of them. Our heat pump noise guide explains what the noise limits mean for where the outdoor unit can go.
Radiators, cylinder and pipework
A heat pump runs at a lower flow temperature than a gas boiler, so each radiator has to be larger to deliver the same heat. A 4-bed house typically has 10 to 14 radiators, and 4 to 7 of them need upsizing. Budget £3,000 to £5,500 for that work. Our radiator sizing guide explains how installers decide which ones to change.
You also need a hot water cylinder, normally 250 to 300 litres for a family of four or five. If you currently have a combi boiler there is no cylinder, so allow £800 to £1,500 for one plus a cupboard or loft space to put it in. If you already have a system boiler with a cylinder, it will usually need replacing anyway, because heat pump cylinders have a larger coil to work at lower temperatures.
The common budget breaker is microbore pipework, the 8 mm or 10 mm pipes fitted in many homes from the 1970s onwards. It restricts flow at heat pump temperatures and often needs replacing with 15 mm or 22 mm pipe at £1,000 to £1,500. Ask the installer to check the pipe sizes during the survey rather than discovering the problem on installation day.
Running costs: 4-bed detached
These figures use the Ofgem price cap for 1 October to 31 December 2026: electricity 26.32p per kWh and gas 7.97p per kWh. Gas rose 9% at this cap change while electricity barely moved, which is why a heat pump on a standard tariff now costs about the same to run as a gas boiler.
| Heating system | Annual cost | Saving vs gas |
|---|---|---|
| Gas boiler | £1,594 | Baseline |
| Heat pump (standard tariff) | £1,634 | -£40 (about level) |
| Heat pump (heat pump tariff) | £1,117 | £477 saving |
| Oil boiler | £1,900 to £2,300 | n/a |
| LPG boiler | £1,900 | n/a |
| Electric boiler | £4,738 | n/a |
18,000 kWh heat demand. Gas at 7.97p/kWh and 90% boiler efficiency. Heat pump COP 2.9 at 26.32p/kWh, or 18p/kWh effective on a well-scheduled heat pump tariff such as Octopus Cosy. Oil at 9.0p/kWh (September 2026 kerosene prices), LPG at 9.5p/kWh. Standing charges excluded.
The tariff makes or breaks the economics. On a heat pump tariff you save £477 a year against gas, which is £9,540 over 20 years. Disconnecting your gas supply saves a further £108 a year in gas standing charge. Read our running costs guide for the full comparison, our tariff guide for how to get an effective rate near 18p, and our electric boiler vs heat pump guide if you heat with electricity today.
Insulation moves these numbers more than any tariff. A well-insulated 4-bed detached with 15,000 kWh of heat demand costs £1,328 a year on gas, £1,361 on a heat pump with a standard tariff and £931 on a heat pump tariff, so the saving stays near £400 a year while every bill is £250 to £300 lower.
The Boiler Upgrade Scheme for a 4-bed
The Boiler Upgrade Scheme pays £7,500 towards an air source or ground source heat pump in England and Wales. Since July 2026, homes replacing an oil or LPG boiler get £9,000. Your MCS-certified installer applies for the grant and it comes off the invoice, so you never handle the money. The scheme was extended to 2030 in April 2026 with a £400 million budget for the current year, and installations carry 0% VAT until March 2027. There is no upper limit on the value of the house or the size of the system, so a 4-bed detached qualifies exactly as a flat does, provided the property has a valid EPC and the heat pump replaces a fossil fuel system. Read our BUS grant guide for the full eligibility rules and our grant checker for everything else you might qualify for.
Is a heat pump worth it for a 4-bed house
Against a new gas boiler at £2,500 to £3,500, a heat pump costs £3,000 to £12,000 more once radiators and the cylinder are included. At £477 a year saving on a heat pump tariff, that is a payback of 6 to 25 years, so the case rests on landing at the low end of the cost range or on being off the gas grid. Against an oil boiler the saving is around £800 a year and the payback drops to 4 to 15 years, before counting the £9,000 grant and the oil tank you no longer need. A heat pump also lasts 20 to 25 years compared with 12 to 15 for a boiler, so over its life it replaces one and a half boilers. Run the numbers for your own house with our boiler vs heat pump comparison, and read heat pump vs new boiler for the 15-year view.
Ground source vs air source for a 4-bed
| System | Installed cost | After grant | Annual running cost |
|---|---|---|---|
| Air source | £11,000 to £16,000 | £3,500 to £8,500 | £1,117 (HP tariff) |
| Ground source | £22,000 to £35,000 | £14,500 to £27,500 | £876 (HP tariff) |
Ground source COP 3.7, needs a 100m+ borehole or 200+ sqm of garden. Both qualify for the £7,500 BUS grant.
For most 4-bed homes air source is the practical choice. Ground source saves roughly £240 a year on a heat pump tariff but costs £10,000 or more extra upfront and needs a drilling rig or a large trench in the garden. It makes sense for a detached house with plenty of land and a long ownership horizon. Read our costs by house type guide for the full comparison across property types.
Getting quotes: what to check
Get three quotes from MCS-certified installers, and compare them on the design rather than the headline price. Each quote should include:
- A room-by-room heat loss calculation with the design outdoor temperature stated.
- The design flow temperature, ideally 50C or lower, and the SCOP the installer expects at that temperature.
- A radiator schedule listing every emitter, which ones change, and their new sizes.
- The cylinder size and where it will go.
- An MCS 020 noise assessment for the outdoor unit position, showing it meets the 42 dB limit at the nearest neighbour's window.
- The warranty on the unit, usually 5 to 7 years, the warranty on the installation, and who you call when something fails.
- Confirmation that the installer will apply for the Boiler Upgrade Scheme and deduct it from the invoice.
Installation takes 2 to 4 days for the heat pump and cylinder, and up to a week if most radiators are being swapped. Check the planning permission rules before you sign. Most 4-bed houses in England are covered by permitted development, but listed buildings and conservation areas are not. Find installers through the MCS installer search.
Reduce noise with anti-vibration pads. Manage your system with a smart thermostat. Track costs with an energy monitor.
Frequently asked questions
How much does a heat pump cost for a 4-bedroom house?
£11,000 to £16,000 installed. The MCS median for all air source installations in 2026 is £12,908. After the £7,500 BUS grant you pay £3,500 to £8,500, or £6,500 to £14,500 with radiators and a cylinder.
What size heat pump does a 4-bed house need?
10 to 14 kW for a detached house, 8 to 10 kW for a semi. The installer's heat loss calculation decides. Insulate first to bring the size and cost down.
How much does it cost to run a heat pump in a 4-bed house?
£1,117 a year on a heat pump tariff, £1,634 on standard electricity, against £1,594 for gas at the October to December 2026 price cap. See our running costs guide.
Which heat pump is best for a 4-bed detached house?
Any 10 to 14 kW unit from Vaillant, Mitsubishi, Daikin or Samsung will heat a 4-bed detached house well. Choose on the installer's design, a flow temperature of 50C or lower and the SCOP in the quote, not on brand. Our heat pump noise guide covers the outdoor unit.
Is a heat pump worth it for a 4-bedroom house?
Yes on a heat pump tariff or off the gas grid. You save £477 a year against gas and around £800 against oil, and the unit lasts 20 to 25 years. Against a cheap boiler replacement on a standard tariff the case is weaker. Compare with our boiler vs heat pump tool.
How long does a 4-bed heat pump installation take?
2 to 4 days for the heat pump, cylinder and controls, and up to a week when most radiators are replaced. The BUS grant is applied by the installer, so there is no waiting on your side.
Data sources
Installed prices from the MCS Data Dashboard (BUS-funded installations, England and Wales, April to June 2026). Energy prices from the Ofgem price cap for October to December 2026. Grant rules from GOV.UK. Cost ranges from Energy Saving Trust and installer market data.