Do I need planning permission?

What permitted development means

Permitted development rights are a national grant of planning permission. They allow certain building works and changes of use without a planning application ⁶. This guide covers England only.

The rules below apply to houses. They do not apply to flats and maisonettes ¹. Planning Portal’s pages are an introduction, not the full legal text, so check with your local planning authority before you start ¹.

Extensions

For all extensions, these limits apply ¹:

• Extensions and other buildings together can cover no more than half the land around the original house.
• The extension cannot be higher than the highest part of the existing roof.
• Eaves cannot be higher than the existing eaves. Within 2m of a boundary, eaves must be 3m or lower.
• No extension forward of the principal elevation, or the side elevation where it fronts a highway.
• Exterior materials must have a similar appearance to the existing house.

Single-storey rear extensions can project 4m beyond the original rear wall on a detached house, or 3m on other houses. They can be up to 4m high ¹.

Side extensions must be single storey, up to 4m high, and no wider than half the width of the original house ¹.

Extensions of more than one storey cannot project more than 3m beyond the original rear wall. They must not be within 7m of the boundary opposite the rear wall ¹.

Larger single-storey rear extensions

Outside designated land and Sites of Special Scientific Interest, the rear limit rises to 8m for a detached house and 6m for other houses ¹. This needs prior approval. You apply to the local authority, which consults your adjoining neighbours ². If neighbours raise concerns or objections, the authority decides whether the effect on their amenity is acceptable ².

Lofts

For a loft conversion that enlarges the roof, the limits are 40 cubic metres for terraced houses and 50 cubic metres for other houses ³. This includes any earlier enlargement ³. Other conditions include ³:

• The enlargement cannot be higher than the existing roof.
• On the principal elevation, where it fronts a highway, it cannot extend beyond the existing roof slope.
• It must be set back at least 20cm from the original eaves, as far as practicable.
• Materials must be similar in appearance to the existing house.
• Side-facing windows must be obscure-glazed. If they open, the opening part must be at least 1.7m above the floor.
• No verandas, balconies or raised platforms.

Outbuildings

Outbuildings and garages must be single storey with eaves no higher than 2.5m ⁴. The overall height limit is 4m with a dual-pitched roof, or 3m for any other roof ⁴. Within 2m of a boundary, the maximum height is 2.5m ⁴. You cannot put an outbuilding forward of the wall forming the principal elevation ⁴. The rules do not cover use as separate self-contained living accommodation ⁴.

Where permitted development does not apply

• Flats and maisonettes. The house rules do not apply to them ¹³.
• Conservation areas and other designated land. Conservation areas count as “Article 2(3) designated land” ¹. There, all side extensions and all rear extensions of more than one storey need householder planning permission, and exterior cladding is not allowed ¹. Loft enlargements under the usual rules do not apply there either ³.
• Listed buildings. Any outbuilding within the curtilage of a listed building needs planning permission ⁴. Works to a listed building may also need listed building consent, which is separate ⁶.
• Article 4 directions, conditions and other limits. A planning condition, an Article 4 direction or another restriction can remove permitted development rights ¹. An Article 4 direction means the work needs a planning application ⁶. A local planning authority or the Secretary of State can make a direction withdrawing specific rights in a defined area ⁶.

Check first with a lawful development certificate

If it is unclear whether permitted development applies, you can apply for a lawful development certificate ⁶. It is a legal document stating whether a past, present or future use or building work is lawful ⁵. It can settle whether a permitted development proposal is legal ⁵. It is not a replacement for planning permission, and anything it does not cover still needs separate permission ⁵.

Where to get help

• Your local planning authority. Planning Portal says to contact it if in doubt, and that councils may charge for pre-application advice ¹.
• The government’s technical guidance for householders, which covers England. It was last updated on 10 September 2019, so check that the rules have not changed ⁷.