In most cases, homeowners do not require planning permission for an air source heat pump, as it is classed as permitted development. However, you should check that your property/area benefits from these permitted development rights (see below).
Air source heat pumps – what can you do under permitted development?
In the legislation, air source heat pump equipment is covered under ‘Class G – The installation, alteration or replacement of a microgeneration air source heat pump
(a) on a dwellinghouse or a block of flats; or
(b) within the curtilage of a dwellinghouse or a block of flats, including on a building within that curtilage.’
Permitted development rules for air source heat pumps
It must comply with MCS or equivalent standards
‘Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards or equivalent standards.’
The MCS are a regulatory body for installers of renewable energy. It’s advisable to choose an MCS regulated installer to ensure standards are met. They also provide a dispute resolution process should anything go wrong.
Only one air source heat pump allowed at the property
‘Development is not permitted by Class G if (a )in the case of the installation of an air source heat pump, the development would result in the presence of more than 1 air source heat pump on the same building or within the curtilage of the building or block of flats.’
You are not allowed to install an air source heat pump if the property already has a wind turbine
‘Development is not permitted by Class G if (b)in the case of the installation of an air source heat pump, a wind turbine is installed on the same building or within the curtilage of the dwellinghouse or block of flats.’
The outdoor unit cannot exceed 0.6 cubic metres
‘Development is not permitted by Class G if the volume of the air source heat pump’s outdoor compressor unit (including any housing) would exceed 0.6 cubic metres.’
It cannot be installed within 1 metre of the boundary
‘Development is not permitted by Class G if any part of the air source heat pump would be installed within 1 metre of the boundary of the curtilage of the dwellinghouse or block of flats.’
It cannot be installed on a pitched roof or within 1m of the edge of a flat roof
‘Development is not permitted by Class G if the air source heat pump would be installed on a pitched roof…[or}…on a flat roof where it would be within 1 metre of the external edge of that roof;’
It cannot be installed on a wall above the ground floor level, if that wall fronts a highway.
‘Development is not permitted by Class G if in the case of land, other than land within a conservation area or which is a World Heritage Site, the air source heat pump would be installed on a wall of a dwellinghouse or block of flats if—
(i)that wall fronts a highway; and
(ii)the air source heat pump would be installed on any part of that wall which is above the level of the ground floor storey.’
Air source heat pumps in a conservation area (or world heritage site)
Thankfully, permitted development does also apply to properties in a conservation area or World Heritage Site. However, the rules stricter when it comes to location:
- You can’t install on a wall or roof that faces a highway.
- It can’t be installed so it’s nearer to any highway which bounds the curtilage than the part of the dwellinghouse or block of flats which is nearest to that highway.
When permitted development doesn’t apply
Permitted development rights relating to solar panels would not apply if:
- your property is listed. If your property is listed you cannot install an air source heat pump without planning permission.
- the site is designated as a scheduled monument.
Conditions of permitted development for air source heat pumps
- The air source heat pump is used solely for heating purposes.
- It’s sited so as to minimise its effect on the external appearance of the building.
- It’s sited, as far as practicable, so as to minimise its effect on the amenity of the area.
- The air source heat pump is removed as soon as reasonably practicable when no longer needed.
How to find an architect for your project
Information contained in this article is for general information only.
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