Single-storey rear extensions

Since 30 May 2013, a change in the law has allowed some homeowners to build larger single-storey rear extensions – up to 8 metres deep for detached houses, and 6 metres deep for all other houses.

If you want to build such an extension (i.e. if it extends between 4 and 8 metres for a detached house, or between 3 and 6 metres for any other house), you must:

  • First notify the Council telling us you want to do this using the application form at the bottom of the page;
  • Pay a fee of £96 (if application is made on or after Monday 19th August 2019) to the Council (please see application form); after which
  • The Council will write to your neighbours inviting their comments on the proposed extension. They have 21 days from the date of our letter to respond;
  • If any comments are received, the Council will take these into account before making a decision (you may wish to discuss your proposal with your neighbours before submitting);
  • A Planning Officer from the Council will come and visit your house to make an assessment; this will require access to the rear garden. The Planning Officer will usually make contact to arrange a convenient time, however they may call unannounced.
  • They will always carry a Council ID card with their photo and name. If you need to verify the ID of the Planning Officer please call 020 8583 2000 or 020 8583 4998.
  • The Planning Officer will take photos of the exterior of your house. If the Planning Officer is unable to conduct a visit or gain full access to your house, your application may be refused.
  • The Planning Officer will not discuss the merits of the application on site, and you should not ask for their views on the application on the visit.
  • The Council will assess your application against The Town and Country Planning (General Permitted Development) (England) Order 2015 (As Amended); and then
  • The Council will notify you within 42 days of receiving your application whether prior approval is given or refused and the reasons why. You must not start building until we have made a decision or following the expiration of 42 days (whichever comes first).

You cannot use this procedure if your property is in a conservation area or is a listed building. Some other exceptions do apply; please consult the relevant legislation and associated guide for details, or contact the planning department for more information.

Please note: All applications will still need to get building regulations approval.  For more information see our Building Control page.

Further information, guidance notes and an application form are available from the Planning Portal: – you can also use the form at the bottom of this page.

Download the application form here

Please note that any views or opinions expressed on this page, while given in good faith, do not necessarily represent a formal decision of the Local Planning Authority unless a statutory application is or has been made and determined in accordance with requisite procedures, planning policies and having had regard to material considerations

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