In this short Blog article, we simplify all the rules regarding rear extensions in the UK so that you can understand whether planning permission is required and what you need to be aware of before construction We cover the permitted development activities and those that are not allowed under permitted development legislation and require permission from the council.

There are different types of rear extensions that you can built. Single storey extensions are the most common and there are also double storey extensions.

Thus would seem to appear straightforward, however, remember, these rights are not universally applicable to all property types. For example, permitted development rights are typically applicable to houses, including detached houses, but exclude flats, maisonettes, converted houses, or other buildings. Therefore, if a single-storey rear extension is your plan, familiarise yourself with your local authority’s specific regulations to avoid any legal issues later on.

The main issues to be aware of are, has less than 50% of the land been taken up. The  proposed extension should not take up more more than 50% of the amenity area.

The extension must be less than 3metres taken from the rear wall of the original house and 4metres for a detached house. The proposed extension must also be no more than 4 metres high.

The materials used to build the extension need to be in keeping with the rest of the property and if the materials are significantlly different, planning permission would be needed.