Planning Policy

Extension in Lambeth

Do you need planning permission for a single-storey extension in Lambeth? Here is what the permitted development rules say, how London Borough of Lambeth’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 Lambeth?

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 Lambeth this matters: the borough has 65 conservation areas and 223 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 Lambeth

How Lambeth’s designations apply

Designation in LambethPublished
Conservation areas65
Article 4 directions (PD removed)223
Listed building outlines950

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 Lambeth 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.

As a London borough, London Borough of Lambeth also decides against the London Plan 2021 (the strategic policy layer for all 33 boroughs), alongside national policy and its own Local Plan.

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 Lambeth address

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

5.0: Questions

Extension in Lambeth, answered

Do I need planning permission for a single-storey extension in Lambeth?
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 Lambeth this matters: the borough has 65 conservation areas and 223 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 Lambeth?
Yes. extension relies on permitted development rights that are restricted on article 2(3) land, which includes conservation areas. London Borough of Lambeth has 65 of them, so inside a boundary you are more likely to need a full application.
How does Lambeth 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 London Borough of Lambeth Local Plan and national policies that apply, verbatim, and shows decided applications nearby.
6.0: More for Lambeth

Other projects in Lambeth