heating
Air Source Heat Pumps in London: Costs, Suitability and Installation
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.