Do I need planning permission or consent for an extension?

If only we could charge a fee for the number of times we get asked and answer that question. Really and truly we can’t give you a complete answer over the phone and need to come and have a look and check what you’re proposing.

There are some “permitted development” rights however which, if your proposal complies, will mean you don’t need to seek planning consent. Our general advice is always to ask. There is usually a duty planning officer available at the local authority planning office who will give an opinion.

Our absolute advice is that if you’re in two minds, don’t guess!

Generally we don’t get too involved in planning applications of a complicated nature. A small uncontentious extension is about as far we go. For bigger and more awkward stuff we work alongside planning specialists, Direct Planning.

We like the planning portal interactive house. It’s easy to use and fairly accurate as well as appealing to the techie in us!

Broadly the provisions for permitted development are:

  • No more than half the area of land around the ‘original house’ would be covered by additions or other buildings.
  • No extension forward of the principal elevation or side elevation fronting a highway.
  • No extension to be higher than the highest part of the roof.
  • Maximum depth of a single-storey rear extension of three metres for an attached house and four metres for a detached house.
  • Maximum height of a single-storey rear extension of four metres.
  • Maximum depth of a rear extension of more than one storey of three metres including ground floor.
  • Maximum eaves height of an extension within two metres of the boundary of three metres.
  • Maximum eaves and ridge height of extension no higher than existing house.
  • Side extensions to be single storey with maximum height of four metres and width no more than half that of the original house.
  • Roof pitch of extensions higher than one storey to match existing house.
  • No verandas, balconies or raised platforms.
  • On designated land no permitted development for rear extensions of more than one storey; no cladding of the exterior; no side extensions.

Want some more info? Email or call. We don’t bite!

The information in this article is for guidance only. There is no substitute for advice specific to your situation. If this is an old post, the law may have changed since it was written.

(Originally published by Steve Way, 17 February 2011)