Key Points for Conservatories and Rear Extension

The key points to think about are:

Site Coverage: You will need planning permission if the proposed conservatory/single storey rear extension (including existing extensions, outbuildings and decking), will cover more than 50% of the land around your home.

Location: If your property fronts a road and you wish to put an extension closer to that road than the principal elevation, you will need planning permission.

Height: Assuming the proposal is only single storey, its max height can be no more than 4 m. If your proposal has an eaves and ridge height greater than that of your property, you will need planning permission. If you are planning on putting an extension within 2 m of a boundary, the eaves height cannot exceed 3 m.

Depth: If you live in an attached house (say a terraced or semi-detached house for example), the max depth is 3 m and 4 m in the case of detached house.

Veranda: You will require planning permission if you wished to add a veranda or raised platform to the structure.

Cladding: , if your house occupies designated land, you cannot clad it.

Planning Permission?

Planning Permission may not be required subject to the following limits and conditions:

  • 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.
  • Max depth of a single-storey rear extension of 3 m for an attached house
  • Max height of a single storey rear extension of 4 m.
  • Max depth of a rear extension of more than 1 storey of 4m including ground floor.
  • Max eaves height of an extension within 3 m of a boundary of 3 m.
  • Max eaves and ridge height of extension no higher than existing house.
  • Side extensions to be single storey with max height of 4 m and width no more than half that of the original house.
  • Roof pitch of extensions higher than 1 storey to match existing house.
  • No verandas, balconies or raised platforms.
  • On designated land* no permitted development for rear extensions of more than 1 storey; no cladding of the exterior; no side extensions.

* The term “original house” means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.
* Designated land includes national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites