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Brentford, Greater London

Kitchen-diner rear extension in Brentford

An open-plan kitchen, dining and family room that opens straight onto the garden. We design, get the approvals for and build kitchen-diner rear extensions in Brentford and the surrounding area, with one contract from the first survey to building control sign-off.

Brentford is covered from our Greater London round, including TW7, TW8 and TW9. For Brentford kitchens we plan the extraction route and the island drainage before the slab is poured, so nothing has to be chased in later.

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 kitchen-diner rear extension cost in Brentford?

A kitchen-diner rear extension in Brentford 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.

Kitchen-diner rear extension prices in Brentford
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

These are guide ranges; the written quote after the survey is the figure that counts.

Do you need planning permission for a kitchen-diner rear extension in Brentford?

Whether your kitchen-diner rear extension in Brentford needs a planning application depends on its size, your house and any local restrictions.

English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.

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.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.

What are homes in Brentford like to extend?

Much of Brentford is 1920s and 1930s semis and short terraces with longer gardens than inner London, which suit full-width single-storey rear extensions. Parking suspensions, skip licences and controlled hours on residential streets shape the programme more than the build itself.

How a kitchen-diner rear extension in Brentford comes together

  1. Look round and measure

    A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.

  2. Drawings and budget

    Floor plans and elevations for the options, each with a guide price.

  3. Approvals

    Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

  4. Written price, then build

    Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.

Kitchen-diner rear extensions near Brentford

Close by, we work in Kew, about 0.9 miles away, and Ealing Common, about 1.5 miles away.

Other work in Brentford:

All rear extensions in Brentford

FAQ

Kitchen-diner rear extension questions in Brentford

How long does a rear extension take to build in Brentford?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

Is the site visit in Brentford free?

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

Should the sink face the garden?

If the plan allows, an island sink or hob facing the glass is a common choice. It needs a floor-level drain run, which is easy to lay in a new slab.

How much does a kitchen-diner rear extension cost in Brentford?

As a guide, £2,470–£4,030 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £29,500–£48,500 at that rate. Your written price follows the survey.

Do you handle building control in Brentford?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Will I need a structural engineer?

Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.

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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