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 Welwyn Garden City?
In Welwyn Garden City, 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 Welwyn Garden City 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 main things that change the cost:
- Underfloor heating and flooring
- Who supplies the kitchen
- Glazing and roof lanterns
- Extension size and roof design
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 Welwyn Garden City?
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
The work we manage on a kitchen extension:
- Kitchen layout planned alongside the extension design
- Building control sign-off
- Electrics, lighting plan and sockets
- Extraction ducted to outside
- Kitchen fitting, worktops and splashbacks
- 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 Welwyn Garden City
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Welwyn Garden City sits in Hertfordshire, about 6 miles west of Hertford. We cover the whole of Welwyn Garden City, including postcodes AL8.
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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about kitchen extensions in Welwyn Garden City
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.
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.
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.
How much does a kitchen extension cost in Welwyn Garden City?
In Welwyn Garden City, 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.
How long does a kitchen extension take in Welwyn Garden City?
Typically 11 to 16 weeks on site, including kitchen fitting. Design and approvals beforehand usually take 6 to 12 weeks.