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 Hampshire?
In Hampshire, 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. That range is adjusted for the South East, where domestic building work typically costs around 12% above the national 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 |
The biggest cost drivers are:
- Extension size and roof design
- Who supplies the kitchen
- Underfloor heating and flooring
- 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 Hampshire?
Before anything is built in Hampshire, we confirm which approvals apply 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
The work we manage on a kitchen extension:
- Drainage and water supply positioned for the sink and appliances
- Electrics, lighting plan and sockets
- Building control sign-off
- Kitchen fitting, worktops and splashbacks
- Kitchen layout planned alongside the extension design
- Flooring and decoration
How long does it take?
Expect 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 Hampshire
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
Towns we cover in Hampshire include Southampton, Portsmouth, Basingstoke, Gosport, Waterlooville and Farnborough.
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 pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about kitchen extensions in Hampshire
Do you build kitchen extensions in Hampshire?
Yes. We build kitchen extensions across Hampshire, including postcodes BH23, BH24, BH25, GU10 and GU11. Every project starts with a free home visit.
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.
Will I need planning permission?
The same rules apply as for any extension. Many single-storey kitchen extensions are permitted development; larger or wraparound designs need an application.
How much does a kitchen extension cost in Hampshire?
In Hampshire, 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.
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.
