What is the larger home extension scheme?
It is a prior approval route in England that allows a single-storey rear extension up to 6 metres deep on a terraced or semi-detached house, or 8 metres on a detached house, without a full planning application. It sits between ordinary permitted development and a householder application.
Who can use it?
Houses, not flats or maisonettes, outside conservation areas, National Parks, National Landscapes, the Broads and Sites of Special Scientific Interest, where permitted development rights have not been removed. The extension must be single-storey, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and built in materials of similar appearance to the house.
How does the process 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.
You send the council a written description, a plan, the depth, height and eaves height, your neighbours' addresses and the fee. The council writes to the adjoining neighbours, who have 21 days to comment. If nobody objects, prior approval is not required. If a neighbour objects, the council judges the effect on their light, outlook and privacy only, not the principle.
What can go wrong?
Starting before the council confirms, or before 42 days have passed, removes the permitted development protection. Building something different from what was submitted does the same. Once built, the council must be told in writing that the work is complete.
Is a 6 metre extension a good idea?
It can be, but daylight is the issue. Six metres puts the old back room a long way from the glass, so a roof lantern or slot rooflight against the house wall is usually essential. Neighbours with a short garden may also feel the depth, so we talk to them before submitting.
About this guide
Written by the Rear Extensions design team and checked against GOV.UK guidance in November 2026. It is general guidance, not legal advice; we confirm the rules for your house at the survey.