What is a kitchen extension?
A kitchen extension is an extension designed around a new kitchen, usually an open-plan kitchen, dining and family space at the back of the house. We build the extension and fit the kitchen as one project, so plumbing, electrics and lighting are planned around the layout from the start.
How much does a kitchen extension cost in Chiswick?
In Chiswick, a kitchen extension typically costs £2,900–£4,400 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £64,000–£97,000. Prices across London are typically 30% above the UK average for this kind of work, which is reflected in the range for Chiswick. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £43,500–£66,000 |
| Typical project (22 m²) | £64,000–£97,000 |
| Larger project (31 m²) | £90,000–£136,500 |
| Rate per m² | £2,900–£4,400 |
What moves the price most:
- Extension size and roof design
- Glazing and roof lanterns
- Island with sink or hob, which needs services in the floor
- Kitchen units, worktops and appliances
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a kitchen extension in Chiswick?
Here is how the rules work for a kitchen extension in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical kitchen extension we handle:
- Electrics, lighting plan and sockets
- Building control sign-off
- Extraction ducted to outside
- Kitchen layout planned alongside the extension design
- Kitchen fitting, worktops and splashbacks
- Flooring and decoration
How long does it take?
The build itself usually takes 11 to 16 weeks on site, including kitchen fitting. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Chiswick
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
From W4 outwards, we take on projects throughout Chiswick and the surrounding parts of Greater London.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about kitchen extensions in Chiswick
How much does a kitchen extension cost in Chiswick?
In Chiswick, a kitchen extension typically costs £2,900–£4,400 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £64,000–£97,000. Your fixed price depends on the survey and drawings.
Do I need extraction to outside?
Building regulations require kitchen extract ventilation. Ducting to an outside wall is the most effective option and is planned during the build.
Who approves a kitchen extension in Chiswick?
Planning matters in Chiswick go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Should the kitchen be designed before the extension?
Yes. Knowing where the sink, hob and island will go lets us place drains, ducting, sockets and windows correctly during the build.
Is underfloor heating worth it?
In a large open-plan space it frees wall space for units and glazing and gives even heat. It is easiest to fit during the build.