Most domestic rooftop solar in Britain is permitted development, which means it does not need a planning application provided it stays inside a set of specific limits. The limits are about projection, position, protected buildings and protected areas, and the exceptions are where almost all the trouble lives. The rules also differ between the four nations.
Do you need planning for solar panels? What permitted development covers
For an ordinary house, roof mounted panels are generally permitted development if they do not project beyond the roof plane by more than a set amount, are not above the highest part of the roof, are sited to minimise their effect on the appearance of the building and on amenity, and are removed when no longer needed. Flats, maisonettes and buildings that are not dwellinghouses are treated differently. Stand alone ground mounted arrays have their own separate and tighter limits.
Solar panels in conservation areas and on listed buildings
On a listed building, listed building consent is a separate requirement from planning permission and is needed for work affecting its character, which panels on a visible roof slope usually do. In conservation areas, national landscapes and World Heritage Sites the permitted development rights are narrower, and panels on a wall or roof slope fronting a highway are commonly excluded. This is where solar slates and tiles earn their cost, and it is also where early informal contact with the conservation officer saves the most time.
Solar panels on new builds: a different route entirely
On a new build the array is part of the building's design and consent, so it is dealt with through the planning permission and building regulations for the house rather than as a retrofit. Energy efficiency requirements for new dwellings have pushed solar onto many new roofs by default. For a buyer, the practical questions are who owns and warrants the array, whether it is registered for export, and whether the certification paperwork comes with the house.
The rules differ by nation, and by building type
England, Scotland, Wales and Northern Ireland each set their own permitted development rules and they are not identical, so a figure quoted from an English guide does not settle a Scottish roof. Commercial and non domestic buildings have their own class of permitted development with different limits again. Check the position for your nation and building type before design, and where there is any doubt a formal confirmation from the local planning authority is cheap compared with taking an array down.
Questions people ask about planning permission solar panels
Is planning permission required for solar panels on a house?
Usually not on an ordinary house, because roof mounted panels are generally permitted development within specific limits on projection, siting and protected buildings. Flats, listed buildings, conservation areas and ground mounted arrays are the common exceptions.
Can you put solar panels on a listed building?
Sometimes, and it needs listed building consent for work affecting its character. Panels on a hidden slope, on an outbuilding or in the form of solar slates are the routes most often accepted. Speak to the conservation officer before design.
What about a conservation area?
Permitted development rights are narrower, and panels on a roof slope or wall fronting a highway are commonly excluded. An application may be needed where a non protected house would not require one.
Are the rules the same across the UK?
No. England, Scotland, Wales and Northern Ireland each set their own permitted development rules, and non domestic buildings have different limits from houses. Check the position for your nation and building type.