This guidance reflects increases to the size limits for single-storey rear extensions which apply between 30 May 2013 and 30 May 2019, and the associated neighbour consultation scheme.
Adding a conservatory to your house is considered to be permitted development, not needing an application for planning permission, subject to the limits and conditions listed below.
- 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.
- Single-storey rear extension must not extend beyond the rear wall of the original house* by more than three metres if an attached* house or by four metres if a detached house.
In addition, outside Article 1(5) designated land* and Sites of Special Scientific Interest the limit is increased to 6m if an attached house and 8m if a detached house until 30 May 2019.
These increased limits (between 3m and 6m and between 4m and 8m respectively) are subject to the neighbour consultation scheme.
- Maximum height of a single-storey rear extension of four metres.
- Extensions of more than one storey must not extend beyond the rear wall of the original house* by more than three metres or be within seven metres of any boundary opposite the rear wall of the house.
- 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.
* 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.
* Attached house means any house that shares a party wall with a neighbouring building.
* Designated land includes national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites.
Please note: The permitted development allowances described here apply to houses and not to:
- Flats and maisonettes (view our guidance on flats and maisonettes)
- Converted houses or houses created through the permitted development rights to change use (as detailed in our change of use section)
- Other buildings
- Areas where there may be a planning condition, Article 4 Direction or other restriction that limits permitted development rights.
Where work is proposed to a listed building, listed building consent may be required.
Please be aware that if your development is over 100 square metres, it may be liable for a charge under the Community Infrastructure Levy
Permitted Development for householders – Technical Guidance
You are strongly advised to read the technical guidance document produced by the Government to help understand how permitted development rules might apply to your circumstances.