Kitchen extensions for homes in Isleworth
From the first sketch to final sign-off, we plan and build kitchen extensions in Isleworth and the surrounding Greater London area.
- Guide price in IsleworthFrom £35,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsTW1, TW3, TW4, TW5, TW7

Working in Isleworth
Postcode districts we cover around Isleworth include TW1, TW3, TW4, TW5, TW7, TW8. Nearby, we also take on projects in Hounslow (1 mile), Heston (2 miles), Richmond (2 miles), Southall (3 miles).
East Molesey, in Surrey, is roughly 5 miles from Isleworth and also on our list. London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
Guide prices for Isleworth
Prices below are for Isleworth, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Isleworth: £2,340 to £4,550 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 5 m 15 m² | £35,000 – £41,000 | £40,500 – £52,000 | £51,500 – £68,500 |
| 4 m × 5 m 20 m² | £46,500 – £55,000 | £54,500 – £69,000 | £68,500 – £91,000 |
| 4 m × 7 m 28 m² | £65,500 – £76,500 | £76,000 – £96,500 | £96,000 – £127,500 |
Build cost only. A mid-range kitchen, supplied and fitted, typically adds £9,000 to £20,000.
For a figure based on your own dimensions, use our guide-price tool.
Included in a typical project
- Kitchen-led layout planning before the drawings are fixed
- Wide sliding or bifold doors to the garden
- Roof lantern or rooflights positioned over the work zones
- Extraction routes and ventilation for building regulations
Will the council need to approve it?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions people ask about kitchen extensions
Do you cover all of Isleworth?
Yes. We cover Isleworth and the surrounding parts of Greater London. Site visits are free and there is no obligation.
Do I need building regulations approval in Isleworth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Isleworth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Where should the island go?
Usually under the brightest part of the roof and away from the main walkway to the garden. We test two or three layouts on the plan before deciding.
Can you fit a kitchen I buy elsewhere?
Yes. We can fit it or work with your supplier’s fitters. We need the layout early so that drains, services and lighting are in the right place.
Book a free site visit in Isleworth
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.