Heat Pumps and Building Regulations: What Homeowners Need to Know

Air source heat pumps (ASHPs) on houses in England are generally permitted development — no planning permission needed — subject to conditions:

• The unit must be at least 1 metre from the property boundary
• Only one heat pump per property under PD
• Not permitted in a conservation area, AONB, National Park or World Heritage Site without planning permission
• The unit must be sited to minimise noise and visual impact (MCS planning guidance)
• Listed buildings always require listed building consent

Ground source heat pumps (GSHPs) involve drilling or ground works — permitted development rules are different and more complex. Always check with your LPA.

Installing a heat pump triggers building regulations in most cases:

• Part J (Combustion Appliances): applies to the heat pump installation itself and any associated flue or ventilation requirements
• Part L (Energy Efficiency): if installing a heat pump as part of building work (e.g. an extension), the whole extension must meet current Part L standards
• Part P (Electrical Safety): heat pumps require electrical connection, which is notifiable work under Part P unless done by a competent person scheme member
• Part F (Ventilation): if a new MVHR system is installed alongside the heat pump, Part F compliance is required

Most heat pump installers are registered under the MCS (Microgeneration Certification Scheme) and can self-certify compliance with building regulations. Always check your installer’s credentials.

For new-build homes: yes, effectively. The FHS prohibits fossil fuel heating as the primary system in new builds. Heat pumps are the dominant compliant solution, though hydrogen-ready boilers and other low-carbon options are technically permitted.

For existing homes and extensions: no. If you are adding an extension to an existing home and using the existing gas boiler to heat it, there is currently no requirement to replace the boiler. The FHS mandate applies to new-build dwellings, not to renovations or extensions of existing homes.

There is ongoing government consultation about extending low-carbon heating requirements to existing homes (the Heat and Buildings Strategy), but no confirmed mandate as of 2026.

Typical installed costs (2026):

• Air source heat pump (ASHP): £8,000–£15,000 installed (before grants)
• Ground source heat pump (GSHP): £15,000–£25,000+ installed

The Boiler Upgrade Scheme (BUS) provides grants of £7,500 for ASHPs and GSHPs. Check eligibility at gov.uk.

Running costs depend heavily on tariff, insulation and property size. An ASHP in a well-insulated home typically produces 3–4 units of heat per unit of electricity consumed (COP of 3–4). At current electricity prices (£0.24/kWh), this compares favourably with gas where the home is well insulated.

Heat pumps work best in well-insulated properties. If your property has poor insulation, improve the fabric first (loft, walls, floor) before switching to a heat pump.

• Check whether the installation is permitted development or needs planning permission (use our PD checker)
• Get at least 3 quotes from MCS-registered installers
• Check eligibility for the Boiler Upgrade Scheme grant
• Confirm the installer will handle building regulations sign-off (most do under competent person schemes)
• Ensure your property’s insulation is adequate before installing — a heat pump in a poorly insulated home will be expensive to run
• For extensions: discuss with your architect whether the extension’s heating design (underfloor heating is ideal with heat pumps, as they run at lower flow temperatures) is compatible with a heat pump