Permitted development rights allow the installation of solar panels. This is subject to the conditions outlined below. 

Permitted development rights also apply to conservation areas, with the exception of those covered by an Article 4 Direction. This removes permitted development rights for solar panel installations. In these cases, you must apply for planning permission. 

To comply with permitted development conditions, you should place the solar panel, so far as is practicable, to reduce its effect on the external appearance of the building and the amenity of the area. You should remove solar panels as soon as they are no longer needed. 

Solar panels mounted on a house or a block of flats or a building in the grounds of a house or flats: 

You need only apply for full planning permission (flats) or householder planning permission (houses) to install a solar panel when any of the following apply: 

• it would protrude more than 20cm from the external surface of the wall or roof slope, when measured perpendicularly 
• the highest part of the solar panel or equipment will be higher than the highest part of the roof. This excludes any chimney 
• it would be installed on a wall in a conservation area which faces a highway. This includes roads, paths and public rights of way 
• your house or flat is a listed building, or within the curtilage of a listed building. Curtilage means within the garden or grounds. 

If your house or flat is a listed building you must also apply for listed building consent. 

Stand alone solar panels on domestic premises (panels not on a building): 

You need only apply for full planning permission (flats) or householder planning permission (houses) to install a stand alone solar panel when any of the following apply: 

• more than one stand alone solar panel would be installed. 
• it would exceed 4m in height. 
• it would be located 5m within the boundary of the property. 
• it would be installed within the curtilage of a listed building. Curtilage means within the garden or grounds. 
• in a conservation area, any part of the solar installation would be closer to a highway than any part of the house. A highway includes roads, paths and public rights of way. 
• the surface area of any stand alone solar panel will exceed 9m² or any dimension of its array (including other equipment) would exceed 3m. 

Ground source heat pumps or water source heat pumps

Generally heat pumps are permitted development for domestic premises. The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended), at Schedule 2, Part 14, states the following:

Class C – installation or alteration etc of ground source heat pumps on domestic premises Permitted development C. The installation, alteration or replacement of a microgeneration ground source heat pump within the curtilage of a dwellinghouse or a block of flats.

Class D – installation or alteration etc of water source heat pumps on domestic premises Permitted development D. The installation, alteration or replacement of a microgeneration water source heat pump within the curtilage of a dwellinghouse or a block of flats.

If your house or flat is a listed building, you may need to apply for listed building consent.