Under permitted development, a single-storey rear extension on a house can go further back than usual if the council gives prior approval. It’s quicker than a full planning application, and the council asks your neighbours first.
No application, up to
- A house that isn’t detached
- 3 m
- A detached house
- 4 m
Prior approval, up to
- A house that isn’t detached
- 6 m
- A detached house
- 8 m
Further than that
- A house that isn’t detached
- A householder planning application
- A detached house
- A householder planning application
| A house that isn’t detached | A detached house | |
|---|---|---|
| No application, up to | 3 m | 4 m |
| Prior approval, up to | 6 m | 8 m |
| Further than that | A householder planning application | A householder planning application |
- 1You applyA description of the work, a plan of the site and the extension, and the fee, sent to the council.
- 2The council asks the neighboursThe owners or occupiers next door, including at the back, can object within 21 days.
- 3The decisionThe council has 42 days. If it hasn’t replied by then, the work can go ahead.
- 4Then building controlPrior approval is planning only. The extension still needs building regulations approval.
The fee is set nationally: see the Planning Portal’s fee schedule.
Before you apply
- Check the house isn’t in a conservation area or an article 4 area
- Talk to the neighbours first
- Wait for the council’s answer, or the 42 days, before work starts
- Apply for building regulations approval as well
What would your job cost?
Describe it, and see a typical price for your area. Then ask builders who do this work.
Read next
How we wrote this
Written by Structa. The rules come from the official pages below. General information, not legal advice.
- GOV.UK: Permitted development rights for householders, technical guidance (checked 16 October 2026)
- Planning Portal: application fees in England (from 1 April 2026) (checked 16 October 2026)
- GOV.UK: Planning permission (checked 6 October 2026)