Isleworth, Greater London
Bungalow rear extension in Isleworth
For homes in Isleworth, a bungalow rear extension is often the simplest way to gain space without moving. Single-storey rear extensions that keep everything on one level. We take it from survey to completion certificate.
Isleworth and its postcode districts TW3, TW5 and TW7 are part of our Greater London coverage. For bungalows in Greater London, a rear extension is the usual way to add space without adding stairs.
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 bungalow rear extension cost in Isleworth?
For Isleworth we work from the London rate: £2,400–£3,900 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 wide × 4 m deep (12 m²) | £29,000–£47,000 |
| 4 m wide × 6 m deep (24 m²) | £57,500–£93,500 |
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 for a bungalow rear extension in Isleworth?
The planning route for a bungalow rear extension in Isleworth is set by England's householder rules and your council.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is 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 Isleworth like to extend?
Much of Isleworth 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 bungalow rear extension in Isleworth comes together
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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
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.
Bungalow rear extensions near Isleworth
From Isleworth, the nearest places we also cover are Osterley (0.6 miles) and Hounslow (0.9 miles).
- Bungalow rear extension in Osterley
- Bungalow rear extension in Hounslow
- Bungalow rear extension in Heston
- Bungalow rear extension in Brentford
- Bungalow rear extension in Richmond
Other work in Isleworth:
FAQ
Bungalow rear extension questions in Isleworth
What postcode areas do you cover around Isleworth?
Including TW3, TW5 and TW7, and the surrounding Greater London area.
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.
Is a bungalow extension cheaper?
The rates are similar per square metre; roof work can add a little.
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 get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do you handle building control in Isleworth?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.