Air Source Heat Pumps in London: Costs, Suitability and Installation
Thinking about an air source heat pump in your London property? Costs, suitability for London homes, government grants available, and realistic running costs compared to gas boilers.
Are Air Source Heat Pumps Suitable for London Properties?
Air source heat pumps (ASHPs) work best in well-insulated properties with large-surface heat emitters (underfloor heating or large radiators). The challenge in London: much of the housing stock is Victorian terraces and converted flats that are:
- Poorly insulated (single brick or solid walls, uninsulated floors)
- Fitted with undersized radiators designed for 80°C flow temperatures (heat pumps deliver 35–55°C)
- Subject to planning constraints in conservation areas
- Not suitable for external unit placement (small gardens, no side access, shared courtyards)
Modern detached and semi-detached London houses built post-1990 with cavity insulation are generally better candidates than Victorian terraces.
Air Source Heat Pump Costs in London
- Air source heat pump supply and installation: £8,000–£15,000
- Boiler Upgrade Scheme grant (2025): £7,500 — reducing cost to £500–£7,500
- Radiator upgrades (if needed): £1,500–£5,000
- Underfloor heating installation (if chosen): £4,000–£12,000 per floor
Running Costs: Heat Pump vs Gas Boiler in London
At current energy prices (electricity ~28p/kWh, gas ~6p/kWh), a heat pump with a coefficient of performance (COP) of 3.0 costs approximately 28/3 = 9.3p per kWh of heat delivered — slightly more than a gas boiler. The economics improve as the government's clean heat incentives increase and as electricity prices fall relative to gas.
Frequently asked questions
Can I get a grant for an air source heat pump in London?
Yes — the Boiler Upgrade Scheme (BUS) provides a £7,500 grant for air source heat pump installations. The grant is paid directly to the MCS-certified installer, reducing the upfront cost. Properties must have a valid EPC with no recommendation to install loft or cavity wall insulation (or have already installed them). Check eligibility on the GOV.UK BUS page.
Do I need planning permission for an air source heat pump in London?
In most cases, no — air source heat pumps in England are permitted development under Class A of Schedule 2 Part 14. However, permitted development rights do not apply if the property is in a conservation area, is a listed building, is in an area of outstanding natural beauty, or if a previous heat pump or wind turbine has already been installed. Many inner London boroughs have extensive conservation areas — check with your local planning authority.
Should London landlords consider heat pumps for rental properties?
Heat pump suitability for London rental properties depends heavily on the property type. A well-insulated 1990s London house may be suitable. A Victorian conversion flat almost certainly is not without significant and expensive improvements. For landlords facing EPC C requirements, a heat pump may not be the most cost-effective route — improving insulation and installing a modern A-rated gas boiler with smart controls may achieve the required EPC rating at lower cost.