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 Stevenage?
In Stevenage, a kitchen extension typically costs £2,400–£3,600 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £53,000–£79,000. Building costs in the East of England run about 6% above the UK average, and the figures for Stevenage are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £36,000–£54,000 |
| Typical project (22 m²) | £53,000–£79,000 |
| Larger project (31 m²) | £74,500–£111,500 |
| Rate per m² | £2,400–£3,600 |
The biggest cost drivers are:
- Who supplies the kitchen
- Underfloor heating and flooring
- Island with sink or hob, which needs services in the floor
- Extension size and roof design
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 Stevenage?
Approvals for a kitchen extension in Stevenage follow the rules for 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Drainage and water supply positioned for the sink and appliances
- Flooring and decoration
- Kitchen fitting, worktops and splashbacks
- Kitchen layout planned alongside the extension design
- Electrics, lighting plan and sockets
- Extension structure, roof and glazing
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 Stevenage
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
We work across Stevenage and neighbouring areas such as Hitchin, Letchworth Garden City and Welwyn Garden City. Postcodes we cover in Stevenage include SG1.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about kitchen extensions in Stevenage
How much does a kitchen extension cost in Stevenage?
In Stevenage, a kitchen extension typically costs £2,400–£3,600 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £53,000–£79,000. Your fixed price depends on the survey and drawings.
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.
Do you build kitchen extensions in Stevenage?
Yes. We build kitchen extensions across Stevenage, including postcodes SG1. Every project starts with a free home visit.
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.
