Larger home extensions

Householders can build larger single-storey rear extensions under permitted development, subject to prior approval. This scheme does not apply to dwellings in conservation areas, flats or maisonettes.

Submit an application for prior approval

An application for prior approval for a larger home extension should be submitted for a proposed single storey rear extension. 

A homeowner or occupier wishing to build a larger single-storey rear extension that: 

• projects more than four metres but no more than eight metres (for detached houses)
• projects more than three metres but no more than six metres (for all other houses)
• would not exceed four metres in height
• would not be located within a Site of Special Scientific Interest

When completing the notification of a proposed larger home extension form you will need to provide:

1. a written description of the proposal including
   • the length that the extension extends beyond the rear wall of the original house 
   • the height at the eaves  
   • the height at the highest point of the extension 
2. a plan of the site, showing the proposed development 
3. the addresses of any adjoining properties, including at the rear 
4. a contact address for the developer / householder and an email address if happy to receive correspondence by email 

We will serve a notice on neighbouring owners / occupiers and those who share a boundary, including to the rear.

If we receive any objections then prior approval would be needed. We will assess the impact of the proposed extension on the amenity of neighbours. We may then either allow the development to go ahead or refuse the application. If we refuse the application then the applicant has a right of appeal to the Planning Inspectorate. We will issue a decision within 42 days from the date we receive a valid application.

If we do not receive any objections, or if we fail to issue a decision with 42 days, then extension will receive approval. Following completion of the extension a completion certificate must be submitted to us.

For further information read Permitted development rights for householders: technical guidance (opens new window).