The short answer is more ”no” than ”yes”. Read on…
Thanks to changes to the planning rules for permitted development on 29th May 2025. Installations in England are covered by The Town and Country Planning (General Permitted Development) (England) Order 2015[i], specifically under Class G of the Order. As a guide whether you need to obtain permission for a heat pump you will need to consider:
Does my home have permitted development rights?
These apply to most homes, but additional planning controls apply to land covered by Article 2(3) which includes properties within;
- Designated Conservation Areas
- Areas of outstanding natural beauty
- A National Park
- The Broads
- A World Heritage Site, or
- An area specified by the Secretary of State for the purposes of section 41(3) of the Wildlife and Countryside Act 1981 (enhancement and protection of the natural beauty and amenity of the countryside)
Permitted development does not apply to Listed buildings. To install an air source heat pump (ASHP) you will need to apply for Listed Building Consent.
Will the installation be covered by MCS planning standards?
Development is not permitted by Class G of the Order unless the air source heat pump complies with the MCS (Microgeneration Certification Scheme Planning Standards. Document MCS-020-a[ii] sets out the sound calculation that must be undertaken for permitted development to be applicable.
The best way to ensure that your installation will be covered here is to use an MCS accredited installer such as Xpert Energy who will undertake assessment as part of their design. Using an MCS installer is also a requirement for accessing the £7500 BUS grant (where eligible[iii]).
Prior to 29th May 2025, ASHPs had to be installed at least 1m from the property boundary but this rule was removed to provide more flexibility in siting the heat pump. However, to reflect that ASHPs may now be closer to a neighbour and potentially cause nuisance, the noise limit was reduced from 42 dB(A) to 37 dB(A). This noise limit is assessed at a point one metre from the centre of a neighbour’s window where the window serves a habitable room (excludes kitchen or bathrooms).
What are the permitted development rules for heat pumps?
Class G of The Town and Country Planning (General Permitted Development) (England) Order 2015 permits installation of ASHP(s) without planning permission in England as follows:
- Up to 2 ASHPs can be installed at detached homes, reflecting possibly higher heat demands for larger properties.
- Other homes including semi-detached, flats and terraces can only install 1 ASHP. If more are required then planning permission is required.
- The size of each ASHP unit cannot exceed 1.5m3 in volume, except for flats where the maximum is 0.6m3.
- No installation is allowed on pitched roofs
- Where installed on a flat roof the unit must be a minimum of 1 metre from the external edge of that roof.
- ASHP cannot be installed if there is also a wind turbine or stand-alone wind turbine installed within the curtilage of the dwellinghouse or block of flats.
- Installation is not permitted on a site designated a scheduled monument
- In the case of land, other than land within a conservation area or which is a World Heritage Site, there is no permitted development if the air source heat pump would be installed on a wall of a dwellinghouse or block of flats if; that wall fronts a highway; and the air source heat pump would be installed on any part of that wall which is above the level of the ground floor storey.
There are specific permitted development rights with respect to ASHPs in Conservation Areas and World Heritage Sites. Here, installation does not have permitted development where the air source heat pump would be installed on a wall or a roof which fronts a highway; or would be installed so that it is nearer to any highway which bounds the curtilage than the part of the dwellinghouse or block of flats which is nearest to that highway; or
Note however that the local authority can apply an “Article 4 Direction” to remove permitted development rights for such properties. This does not necessarily mean that an ASHP cannot be installed, but does mean that to do so would require planning permission to be granted.
Summary
A location can now be identified for an ASHP, or ASHPs to be installed at most properties in England under Permitted Development. Some different rules apply in other parts of the UK.
For advice on the design and installation of heat pumps contact Xpert Energy on 0118 930 3600 (option 1) or email installs@xpertenergy.co.uk
[i] The Town and Country Planning (General Permitted Development) (England) Order 2015
[ii] MCS-020-a-Issue-1.1-Final.pdf
[iii] Apply for the Boiler Upgrade Scheme: Overview – GOV.UK