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 Sevenoaks?
In Sevenoaks, a kitchen extension typically costs £2,500–£3,800 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £55,000–£83,500. We start from a UK-wide guide and adjust it for the South East, where labour and materials are typically about 12% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £37,500–£57,000 |
| Typical project (22 m²) | £55,000–£83,500 |
| Larger project (31 m²) | £77,500–£118,000 |
| Rate per m² | £2,500–£3,800 |
What moves the price most:
- Glazing and roof lanterns
- Extension size and roof design
- Island with sink or hob, which needs services in the floor
- Who supplies the kitchen
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a kitchen extension in Sevenoaks?
Whether you need planning permission depends on your house and its location 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Extension structure, roof and glazing
- Kitchen fitting, worktops and splashbacks
- Flooring and decoration
- Drainage and water supply positioned for the sink and appliances
- Kitchen layout planned alongside the extension design
- Building control sign-off
How long does it take?
The build itself usually takes 11 to 16 weeks on site, including kitchen fitting. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Sevenoaks
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
Projects in Sevenoaks (TN13) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about kitchen extensions in Sevenoaks
Who approves a kitchen extension in Sevenoaks?
Planning matters in Sevenoaks go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How long will I be without a kitchen?
Usually 3 to 6 weeks at the end of the job, once the back wall is opened and the new kitchen goes in. We can help set up a temporary kitchen.
Can I buy my own kitchen?
Yes. You can supply it and we fit it, or we supply it as part of the price. Either way we coordinate deliveries with the build programme.
How much does a kitchen extension cost in Sevenoaks?
In Sevenoaks, a kitchen extension typically costs £2,500–£3,800 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £55,000–£83,500. 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.
