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Chiswick, Greater London

Single-storey rear extension in Chiswick

Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design, get the approvals for and build single-storey rear extensions in Chiswick and the surrounding area, with one contract from the first survey to building control sign-off.

Chiswick sits in Greater London, with postcode districts including W3, W4 and W6. A depth of 3 to 4 metres keeps many single-storey rear extensions in Chiswick within permitted development, subject to the house's planning history.

Book a free site visit

Tell us about the house and we'll call to arrange a free, no-obligation visit.

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

In Chiswick, our guide for a single-storey rear extension is £2,470–£4,030 per square metre including VAT for a standard specification. 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 prices in Chiswick
SizeGuide 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

Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.

Do you need planning permission for a single-storey rear extension in Chiswick?

The planning route for a single-storey rear extension in Chiswick is set by England's householder rules and your council.

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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.

What are homes in Chiswick like to extend?

Much of Chiswick is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.

How a single-storey rear extension in Chiswick comes together

  1. Free site visit

    We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

  2. Options and costs

    We draw layout options and price each one, so the budget shapes the design rather than surprising you later.

  3. Planning and regulations

    We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.

  4. Build and sign-off

    We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.

Single-storey rear extensions near Chiswick

We also build single-storey rear extensions in nearby Acton (1.4 miles) and Barnes (1.4 miles).

Other work in Chiswick:

All rear extensions in Chiswick

FAQ

Single-storey rear extension questions in Chiswick

Do I need a party wall agreement?

In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.

What postcode areas do you cover around Chiswick?

Including W3, W4 and W6, and the surrounding Greater London area.

Do I need a structural engineer?

Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.

Can you match the brick or stone on my Chiswick house?

We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.

Is the site visit in Chiswick free?

Yes. We visit, measure up and talk through the options with no cost and no obligation.

Can I live at home while the extension is built?

Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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