Greater London

Single-storey rear extensions in Greater London

Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design and build rear extensions across Greater London, from Islington and Bexley to Barking, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.

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Single-storey rear extension with white render, anthracite sliding doors and a roof lantern on a 1930s semi-detached house

On 1930s semis and post-war houses like those around Islington, a single-storey rear extension is usually the simplest way to fix a small back kitchen without touching the bedrooms. Greater London is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.

How much does a single-storey rear extension cost in Greater London?

A single-storey rear extension in Greater London is priced at £2,470–£4,030 per square metre including VAT as a guide, before kitchen fit-out and fees. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.

Single-storey rear extension guide prices in Greater London
Size	Guide price inc VAT
3 m wide × 4 m deep (12 m²)	£29,500–£48,500
4 m wide × 5 m deep (20 m²)	£49,500–£80,500
4 m wide × 6 m deep (24 m²)	£59,500–£96,500

We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.

Do you need planning permission in Greater London?

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.

If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.

Where in Greater London do we work?

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FAQ

Questions people ask

How deep can a single-storey rear extension be without planning?

In England, 3 metres on an attached house and 4 metres on a detached house under permitted development, or up to 6 and 8 metres with prior approval. Wales allows 4 metres; Scotland and Northern Ireland have their own limits.

Is a flat roof or a pitched roof better?

A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.

Can I stay in the house during the build?

Usually yes. The noisiest, dustiest stage, removing the back wall, is kept to the final weeks and screened off. Most families set up a temporary kitchen elsewhere in the house.

Do you cover all of Greater London?

We cover 187 towns and districts in Greater London, including Islington, Bexley and Barking.

Who builds the extension?

Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.