What is Permitted Development?

Permitted development rights allow householders to improve and extend their homes without the need to apply for planning permission. Permitted Development is a permission granted not by the Local Authority but by Parliament (General Permitted Development) (England) Order 2015 for which a Certificate for a Lawful Proposed Use or Development can be obtained.

Outbuildings (including garages), leisure complexes, single storey extensions such as garden rooms, orangeries and porches and even two storey extensions can be considered permitted development and therefore do not require an application for planning permission1, subject to the following limits and conditions:


  • • They do not project in front of any wall that forms part of the principle elevation.
  • • They are of single storey construction, with a maximum eaves height of 2.5 metres and are no more than 4 metres high at the ridge if they have a dual pitch roof or 3 metres if they have any other form of roof.
  • • Any building, enclosure or container within 2 metres of the boundary is a maximum of 2.5 metres high.
  • • There are no raised platforms, balconies, or verandas.
  • • At least half the area surrounding the ‘original house’ remains uncovered by other buildings or additions. Sheds, all outbuildings and extensions must be included when calculating this 50% limit.
  • • Any new outbuilding must not itself be separate self-contained living accommodation and must not have a microwave antenna.
  • • On designated land (National Parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites) any outbuilding sited more than 20 metres from any wall of the house is limited to 10 square metres.
  • • On designated land planning permission is required for buildings, enclosures, containers and pools to the side of a property.
  • • Within the curtilage of a listed building planning permission is required for any outbuilding.


  • • The ground area measured externally must not exceed three square metres.
  • • The highest part of the porch should not exceed three metres above ground level.
  • • No part of the porch is to be within two metres of any boundary that fronts a highway.
  • • Permitted Development Advice
  • • Permitted Development Guidance

Single storey extensions:

  • • Extensions (including previous extensions) and other buildings must not exceed 50% of the total area of land around the original house. (Including sheds and other outbuildings).
  • • Extensions forward of the principal elevation of a house are not permitted development.
  • • On designated land side extensions are not permitted development.
  • • Materials used in exterior work to be similar in appearance to those of the existing house.
  • • Width of side extension must not have a width greater than half the width of the original house.
  • • If extension is within two metres of a boundary, maximum eaves height should be no higher than three metres to be permitted development.
  • • Single storey extension must not extend beyond the rear of the original house by more than 3m if an attached house or by 4m if a detached house. Increased limits may be permissible under the neighbour consultation scheme.
  • • Single storey rear extensions must not exceed a height of four metres.
  • • Maximum eaves and ridge height of extension no higher than existing house.

Two storey rear extensions:

  • • Criteria similar to single storey extensions except:-
  • • Extensions of more than one storey must not extend beyond the rear wall of original house by more than three metres or be within seven metres of any boundary opposite the rear wall of the house.
  • • Roof pitch of extensions higher than one storey to match that of the existing house, as far as is practicable.
  • • Any upper floor window in a wall or roof slop-e in a side elevation must be obscure glazed and non-opening unless the parts which can be opened are more than 1.7 metres above the floor level of the room in which it is installed.
  • • No balconies or verandas are permitted development.

Permitted Development is not always black and white and if there any questions or doubt we strongly suggest checking with the Local Authority Planning Department. For proof that your building work proposal complies with Permitted Development we recommend applying for a Lawful Development Certificate.

Properties located within the Green Belt may have restricted development opportunities to ensure open space is maintained and urban sprawl is restricted. However, in some cases, Permitted Development may allow further development.

If your project does not qualify as permitted development you will need to submit a planning application.

1 The property owner must confirm that Permitted Development Rights exist with their property and can seek further clarification from the Local Authority Planning Department.

N.B. The term ‘original house’ refers to 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.