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Planning Permission

Under new regulations that came into effect on 1 October 2008 an extension or addition to your home is considered to be permitted development, not requiring an application for planning permission, 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.
  • Maximum depth of a single-storey rear extension of three metres beyond the rear wall for an attached house and four metres beyond the rear wall 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 beyond the rear wall 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.
  • Two-storey extensions no closer than seven metres to rear boundary.
  • Roof pitch of extensions higher than one storey to match existing house.
  • Materials to be similar in appearance to the existing house.
  • No verandas, balconies or raised platforms.
  • Upper-floor, side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
  • On designated land* no permitted development for rear extensions of more than one storey.
  • On designated land no cladding of the exterior.
  • On designated land no side extensions.

 

Installation, alteration or replacement of a chimney, flue or soil and vent pipe: Read guidance on the permitted development regime under Class G of the regime which came into force on 1 October 2008.

* 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.

Common projects: Extensions

Building Regulations

Most extensions of properties require approval under the Building Regulations.

There are a number of classes of new buildings or extensions of existing buildings that do not need Building Regulations approval, i.e. are exempt from the Regulations.

Read more about exemptions (In our Professional Users section).
Read more about extensions and building regulations.

Disclaimer: this is an introductory guide and is not a definitive source of legal information. Read the full disclaimer here.

NOTE: This guidance relates to the planning regime for England. Policy in Wales may differ. If in doubt contact your Local Planning Authority.