Planning Policy

Extension in North Somerset

Do you need planning permission for a single-storey extension in North Somerset? Here is what the permitted development rules say, how North Somerset Council’s designations change them, and what decides an application, grounded in the official guidance and quoted verbatim.

Modern glazed extension against a classical stone house
New glass against old stone: the extension question every authority weighs
The short answer

Do you need planning permission for a single-storey extension in North Somerset?

Many single-storey rear extensions are permitted development under Class A, within set limits on depth, height and how much of the garden they cover, so no planning application is needed. In North Somerset this matters: the borough has 39 conservation areas and 38 Article 4 directions, and inside those the permitted development route narrows or is removed, so a single-storey extension can need a full application where it would not two streets away.

1.0: The permitted development position

The starting point

Many single-storey rear extensions are permitted development under Class A, within set limits on depth, height and how much of the garden they cover, so no planning application is needed.

“This provides permitted development rights for the enlargement, improvement or other alteration of a house.”PD technical guidance, Class A · full text in the library → · official source →
2.0: What changes it in North Somerset

How North Somerset’s designations apply

Designation in North SomersetPublished
Conservation areas39
Article 4 directions (PD removed)38
Listed building outlines1,084

Because extension depends on permitted development rights restricted on article 2(3) land, the conservation areas above are decisive: inside one, expect to need a full application. Counts are read live from planning.data.gov.uk; your report checks them against your exact address.

3.0: How it’s decided

What North Somerset weighs

Where an application is needed, design does the deciding: depth against the neighbouring rear walls, loss of light, roof form, and materials against the parent building.

Read the full extension guide →

4.0: A worked example

See a single-storey extension in a real report

London’s most common project: a kitchen extension behind a Victorian terrace in a conservation area with an Article 4 direction. 262 nearby decisions, 81% approved.

Read the rear extension in clapham case study →

Your report

Get a planning report for your North Somerset address

A Planning Policy report reads the designations on your exact North Somerset address, quotes the North Somerset Council and national policies that apply to a single-storey extension, and (on Pro) shows decided applications nearby with outcomes.

5.0: Questions

Extension in North Somerset, answered

Do I need planning permission for a single-storey extension in North Somerset?
Many single-storey rear extensions are permitted development under Class A, within set limits on depth, height and how much of the garden they cover, so no planning application is needed. In North Somerset this matters: the borough has 39 conservation areas and 38 Article 4 directions, and inside those the permitted development route narrows or is removed, so a single-storey extension can need a full application where it would not two streets away.
Does a conservation area affect a single-storey extension in North Somerset?
Yes. extension relies on permitted development rights that are restricted on article 2(3) land, which includes conservation areas. North Somerset Council has 39 of them, so inside a boundary you are more likely to need a full application.
How does North Somerset decide a extension application?
Where an application is needed, design does the deciding: depth against the neighbouring rear walls, loss of light, roof form, and materials against the parent building. A Planning Policy report quotes the specific North Somerset Council Local Plan and national policies that apply, verbatim, and shows decided applications nearby.
6.0: More for North Somerset

Other projects in North Somerset