Brentford, Greater London
Two-storey rear extension in Brentford
We plan and build two-storey rear extensions for homeowners in Brentford. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
Brentford sits in Greater London, with postcode districts including TW7, TW8 and TW9. In Brentford, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
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 two-storey rear extension cost in Brentford?
For Brentford we work from the London rate: £2,340–£3,510 per square metre of new floor, including VAT, standard specification. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £70,000–£105,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £112,500–£168,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a two-storey rear extension in Brentford?
Here is how the rules in England apply to a two-storey rear extension in Brentford.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
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 two-storey rear extension in Brentford comes together
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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Two-storey rear extensions near Brentford
Close by, we work in Kew, about 0.9 miles away, and Ealing Common, about 1.5 miles away.
- Two-storey rear extension in Kew
- Two-storey rear extension in Ealing Common
- Two-storey rear extension in Isleworth
- Two-storey rear extension in Richmond
- Two-storey rear extension in West Ealing
Other work in Brentford:
FAQ
Two-storey rear extension questions in Brentford
Is the site visit in Brentford free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.
Can I add an en-suite upstairs?
Yes. We plan the soil pipe route early so the bathroom sits where drainage works without boxing through the room below.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
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.
What postcode areas do you cover around Brentford?
Including TW7, TW8 and TW9, and the surrounding Greater London area.