From 30 May 2013, for a period of six years only, the Government has increased the size of single-storey rear extensions that can be built under permitted development, and has brought into force the associated neighbour consultation scheme.
Please Note: This scheme does not apply to dwellings in conservation areas, nor does it apply to flats or maisonettes.
Single-storey rear extensions
For a temporary period householders will be able to build larger single-storey rear extensions under permitted development. The size limits will double from 4 metres to 8 metres for detached houses, and from 3 metres to 6 metres for all other houses. These measurements must be taken from the rear elevation of the original house as originally built or as it stood on 1 July 1948. Remember that even if you have not built a rear extension, a previous owner might have.
The development must however comply with all other relevant limitations and conditions that apply to other rear extensions allowed under permitted development, for example:
- No more than half the area of land around the "original house" should be covered by additions or other buildings. "Original house" means as it was originally built or as it stood on 1 July 1948.
- The maximum depth of the single-storey rear extension is 6m for an attached house and 8m for a detached house. Measurements should be taken from the rear elevation of the house as originally built or as it stood on 1 July 1948.
- The maximum height* of the single-storey rear extension is 4m.
- The maximum eaves height* should be 3m if the extension is within 2m of any boundary.
- Materials used in construction should be similar in appearance to those used for the existing house.
- No verandas, balconies or raised platforms are permitted.
- No chimneys, flues, soil and vent pipes or microwave antennae are permitted.
* Height is measured externally from the highest point of the natural surface ground adjacent to the development.
For a full list of the limitations and conditions, please see the Planning Portal.
To benefit from these permitted development rights, the extension must be completed on or before 30 May 2019 and the developer must notify the Council in writing when the development has been completed.
If your require formal confirmation that the extension complies with permitted development, you can also apply for a Certificate of Lawfulness. This may be useful when you come to sell your property.
The extension must be built in accordance with the details approved by the local planning authority (or, if no objections were raised, the details submitted), unless the local planning authority agrees any changes in writing.
The Neighbour Consultation Scheme
These new larger extensions (ie. if they extend between 4 and 8 metres, or between 3 and 6 metres) must go through the following process:
1. A homeowner wishing to build a larger single-storey rear extension must notify the local planning authority (the Council) and provide:
- a written description of the proposal, which includes the length that the extension extends beyond the rear wall of the original house, the height at the eaves and the height at the highest point of the extension;
- a site location plan, showing at least two named roads;
- a block plan (at a scale of 1:100 or 1:200) of the existing house and proposed extension, showing distances to boundaries
- scaled plans (at 1:50 or 1:100) including existing and proposed floor plans and elevations, indicating the position of any doors or windows, and a roof plan.
- the addresses of any adjoining properties, including at the rear;
- a contact address for the developer and an email address if the developer is happy to receive correspondence by email.
There is no fee required. An application form and checklist can be downloaded below.
The local planning authority may ask for further information if it needs it to make a decision on the application.
2. The Council will notify the adjoining owners or occupiers of the development and will set out when the application was received and when the 42-day determination period ends. It will also say how long neighbours have to make objections (which will be a minimum of 21 days), and the date by which objections must be received.
3. If any adjoining neighbour raises an objection within the 21-day period, the Council will take this into account and make a decision about whether the impact on the amenity of all adjoining properties is acceptable. The Council is not allowed to consider any other issues or objections from any other third parties.
4. The development may go ahead if no objections are received from adjoining neighbours within the 21-day period and the development complies with all the relevant criteria, or if objections have been received, that following consideration the Council decides that the effect on the amenity of adjoining properties is acceptable.
5. The Council may refuse the application if the proposal does not comply with the limitations and conditions that apply under permitted development or if you have supplied insufficient evidence for us to establish if the proposal complies with these limitations and conditions.
6. The Council must notify the developer of its decision within the 42-day determination period.
7. The Council may grant permission unconditionally or with conditions relating to the impact of the proposed extension on the amenity of any adjoining premises.
8. If approval is refused, the householder may appeal.
This scheme does not apply to dwellings in conservation areas or to flats or maisonettes. To find out if your property is in a conservation area, please use our Local Information Service on our website.
The history of your property should also be checked in order to determine whether your permitted development rights have been removed by the Council as the Local Planning Authority. If they have, this guidance will not apply to you.
Date of last review: 16 February 2016
How to apply
To ensure that you supply the Council with all the information it requires, please use the application form and checklist below.