Kew, Greater London
Semi-detached rear extension in Kew
Thinking about a semi-detached rear extension in Kew? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover Kew (TW8, TW9 and W4) as part of our Greater London work. In Kew we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 semi-detached rear extension cost in Kew?
In Kew, our guide for a semi-detached 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.
| 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Kew?
Planning for a semi-detached rear extension in Kew follows the English householder rules.
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.
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.
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 Kew like to extend?
Much of Kew 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 semi-detached rear extension in Kew 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.
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.
Semi-detached rear extensions near Kew
Neighbouring places we cover include Brentford (0.9 miles) and Mortlake (1.2 miles).
- Semi-detached rear extension in Brentford
- Semi-detached rear extension in Mortlake
- Semi-detached rear extension in Chiswick
- Semi-detached rear extension in East Sheen
- Semi-detached rear extension in Richmond
Other work in Kew:
FAQ
Semi-detached rear extension questions in Kew
Is the site visit in Kew free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Kew?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
What postcode areas do you cover around Kew?
Including TW8, TW9 and W4, and the surrounding Greater London area.
Can you match the brick or stone on my Kew house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.