Larger home extension prior approval (England)

How does prior approval work?

England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.

The council only considers the effect on adjoining neighbours' amenity, and only if a neighbour objects. If nobody objects, prior approval is not required and you can build once the council confirms or the 42 days pass without a decision. When the extension is finished you must tell the council in writing that it is complete.

What does it cost?

Our drawings and prior approval submission typically cost £1,000–£2,200 including VAT, plus the council fee. A 6 m deep extension is priced like any single-storey rear extension: a 4 m wide × 6 m deep extension is typically £45,500–£74,500.

Is it available in Wales, Scotland or Northern Ireland?

No. The scheme only applies in England. Elsewhere, an extension deeper than permitted development goes through a householder planning application.

What is included?

• Eligibility and designated land check
• Neighbour impact review
• Prior approval drawings
• Submission (council fee paid separately)
• Responses to neighbour comments
• Completion notice to the council
• Building Regulations drawings
• Build to the approved depth

Guide prices by region

Per square metre of new floor, including VAT, standard specification.