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 Southampton?
In Southampton, 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. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Southampton. 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 |
The biggest cost drivers are:
- Glazing and roof lanterns
- Underfloor heating and flooring
- Extension size and roof design
- Who supplies the kitchen
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a kitchen extension in Southampton?
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
On a typical kitchen extension we handle:
- Extension structure, roof and glazing
- Drainage and water supply positioned for the sink and appliances
- Building control sign-off
- Kitchen fitting, worktops and splashbacks
- Extraction ducted to outside
- Flooring and decoration
How long does it take?
The build itself usually takes 11 to 16 weeks on site, including kitchen fitting. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Southampton
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.
From SO15 outwards, we take on projects throughout Southampton and the surrounding parts of Hampshire.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about kitchen extensions in Southampton
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.
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.
How much does a kitchen extension cost in Southampton?
In Southampton, 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.
Who approves a kitchen extension in Southampton?
Planning matters in Southampton 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.
