A heat pump for a UK flat costs roughly twice as much to install as a gas boiler, but can cut annual heating bills by up to 40%, a saving worth around £250 per year for an average flat.
If you live in a flat and are considering replacing your gas boiler or electric heating, a heat pump is likely the most efficient low-carbon option on the market. The upfront cost is higher than a gas boiler, but the long-term running cost savings and government grants make it a financially viable choice for many flat owners.
Based on 2026 data, a typical 2-bedroom flat switching from a gas boiler to an air-to-water heat pump can expect to save roughly £250 per year on heating bills, while a flat currently using electric storage heaters could save up to £340 per year (Energy Saving Trust, 2026).
The two main heat-pump types for UK flats are air-to-water and air-to-air
Choosing the right type depends on your flat’s existing heating system and your hot water needs. The two most common options for flats are air-to-water and air-to-air heat pumps.
- Air-to-water systems use your existing radiators or underfloor heating to distribute heat and also provide hot water. They are the most common choice for flats with wet central heating already installed. Installation typically costs between £6,000 and £11,000 (MCS, 2026).
- Air-to-air systems use wall-mounted fan units to blow warm air directly into rooms. They are cheaper to install (roughly £3,000–£6,000) but do not supply hot water, so you would need a separate system for showers and taps (Energy Saving Trust, 2026).
Both types extract heat from outside air, even at temperatures below freezing, and are classed as renewable heating under the Renewable Heat Incentive. For most flats with an existing gas boiler and radiator system, an air-to-water heat pump is the more practical choice because it replaces both heating and hot water.
Quick numbers cost, efficiency, and running cost comparison for a 2-bedroom flat
The table below compares a gas boiler baseline with the two main heat pump types for a typical 2-bedroom flat in the UK. All figures are based on 2026 data and assume an EPC Band C flat with average insulation.
| Heating system | Typical installation cost (GBP) | Annual running cost (GBP) | Efficiency (CoP / SCoP) | Annual CO₂ saving (kg) | Suitable for flats without outdoor space |
|---|---|---|---|---|---|
| Gas boiler (baseline) | £2,500–£4,000 | £550–£650 | 90% efficiency | 0 (baseline) | Yes |
| Air-to-water heat pump | £6,000–£11,000 | £350–£450 | 3.0–3.5 SCoP | 1,200–1,500 kg | No (needs outdoor unit) |
| Air-to-air heat pump | £3,000–£6,000 | £300–£400 | 3.5–4.0 SCoP | 1,500–1,800 kg | No (needs outdoor unit) |
Running costs are based on Ofgem’s 2026 typical domestic consumption values for a 2-bedroom flat (around 7,500 kWh/year for heating and hot water) (Ofgem, 2026). The CO₂ saving assumes the grid’s average carbon intensity for 2026.
A heat pump can save you up to £340 per year on heating bills depending on your flat’s insulation and current fuel
The savings you achieve depend heavily on what you are replacing and how well your flat retains heat. If you currently heat with electric storage heaters, switching to an air-to-water heat pump saves roughly £300–£340 a year, because electricity is much more expensive per kWh than gas (Energy Saving Trust, 2026).
If you currently heat with mains gas, the saving is smaller, around £150–£200 a year, because gas is cheaper per kWh. The higher your flat’s insulation (EPC Band C or better), the larger the heat pump’s efficiency advantage, because a well-insulated home requires less heat output and the pump can run at a lower flow temperature (DESNZ, 2026).
For flats with very poor insulation (EPC Band E or F), the savings will be lower, and the heat pump may struggle to keep the property warm without significant draught-proofing or fabric upgrades first.
You can get a £7,500 grant for a heat pump in a flat through the Boiler Upgrade Scheme
The Boiler Upgrade Scheme (BUS) offers a flat-rate £7,500 grant for air-to-water heat pumps in England and Wales. This grant is available to homeowners and landlords of flats, and does not require your flat to have a boiler beforehand, it can replace any existing heating system (GOV.UK, 2026).
The grant application is made by the installer before installation, and the cost is deducted from your invoice. The scheme runs until March 2028, with no cap on the number of applications per property. However, the grant is only available for air-to-water heat pumps, not air-to-air systems. If you choose an air-to-air heat pump, you will not qualify for the BUS grant, but you may still benefit from the lower installation cost.
For flats in Scotland, separate grants are available through Home Energy Scotland, which offers up to £7,500 for heat pumps plus an additional £1,500 for insulation improvements.
The installer must be MCS-certified for the Boiler Upgrade Scheme grant, and TrustMark registration is also required
To claim the BUS grant, the installer must hold valid MCS (Microgeneration Certification Scheme) certification for the specific heat pump product being installed. MCS certification proves the installer meets quality standards for heat pump design and installation (MCS, 2026).
Also, the installer must be registered with TrustMark, a government-endorsed quality mark that covers consumer protection and complaints handling (TrustMark, 2026). For flats specifically, the installer must also confirm that the outdoor unit can be sited without breaching leasehold or planning restrictions. You should ask the installer to check these conditions before proceeding.
Using an uncertified installer means you lose the £7,500 grant and may also invalidate your building warranty or home insurance.
The direct answer yes, a heat pump is a suitable heating system for a UK flat, provided the flat has adequate insulation and a suitable outdoor location for the unit
Most UK flats can accommodate a heat pump if they have a balcony, a flat roof, a wall bracket, or a communal garden area. The key requirements are an EPC rating of at least Band C, space for the outdoor unit (typically 1m x 1m), and no leasehold restrictions against external alterations (Energy Saving Trust, 2026).
Air-to-water heat pumps require a hot water cylinder, so the flat must have space for one (typically 1.5m tall, 0.6m diameter). For flats without outdoor space, air-to-air heat pumps or shared ground-source systems are alternative options, though less common. If your flat is part of a communal heating network, a heat pump may still be installed as a backup or top-up system, but you should check with the network operator first.
If your flat has an EPC rating of Band D or lower, you may need to improve insulation (loft insulation, double glazing, or draught-proofing) before a heat pump can deliver its full efficiency benefits.
The planning and leasehold steps for a heat pump in a flat are straightforward but must be checked before you buy
Planning permission is not normally required for air source heat pumps in England, but flats in conservation areas or listed buildings may need it. The outdoor unit must comply with noise limits (42 dB(A) at 1m from the nearest neighbour’s window) under permitted development rules (GOV.UK, 2026).
Leasehold flats require written permission from the freeholder or management company before installation. You should request this in writing and allow up to 8 weeks for a response. If the flat is part of a communal heating network, a heat pump may still be installed as a backup or top-up system, but you will need the network operator’s approval (Leasehold Advisory Service, 2026).
For flats without a balcony or garden, wall brackets are a common solution, but they must be approved by the freeholder and may require a structural survey. heat pump installation checklist for leasehold flats Boiler Upgrade Scheme eligibility for flats
Frequently Asked Questions
An air-to-water heat pump costs between £6,000 and £11,000 installed, while an air-to-air system costs roughly £3,000 to £6,000 (MCS, 2026). The final price depends on your flat's existing heating system and installation complexity.
Yes, you can install a heat pump in a flat without a garden if you have a balcony, external wall, or a shared roof space for the outdoor unit (Energy Saving Trust, 2026). You will need landlord permission if you rent.
A 2-bedroom flat typically needs a heat pump with a capacity of 4 to 6 kW (MCS, 2026). The exact size depends on insulation, floor area, and heating demand.
Modern heat pumps produce sound levels between 40 and 60 decibels, similar to a fridge or a quiet conversation (Energy Saving Trust, 2026). Installing the outdoor unit away from bedrooms and on anti-vibration mounts reduces disturbance.
Yes, a heat pump is cheaper to run than a gas boiler in a flat, saving roughly £250 per year for an average 2-bedroom flat (Energy Saving Trust, 2026). Running costs are lower because heat pumps are 3-4 times more efficient.
