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 South Glamorgan?
In South Glamorgan, a kitchen extension typically costs £2,050–£3,150 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £45,000–£69,500. We start from a UK-wide guide and adjust it for Wales, where labour and materials are typically about 8% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £31,000–£47,000 |
| Typical project (22 m²) | £45,000–£69,500 |
| Larger project (31 m²) | £63,500–£97,500 |
| Rate per m² | £2,050–£3,150 |
The main things that change the cost:
- Who supplies the kitchen
- Island with sink or hob, which needs services in the floor
- Underfloor heating and flooring
- Glazing and roof lanterns
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 South Glamorgan?
Whether you need planning permission depends on your house and its location in Wales. In Wales a single-storey rear extension is often permitted development: up to 4 metres beyond the rear wall and up to 4 metres high, with eaves no higher than 3 metres within 2 metres of a boundary and no more than half the land around the original house covered. Wales has no larger home extension prior approval route, so deeper extensions need a planning application, as do extensions to flats, listed buildings and houses whose rights have been removed.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most kitchen extensions:
- Kitchen fitting, worktops and splashbacks
- Building control sign-off
- Extraction ducted to outside
- Kitchen layout planned alongside the extension design
- Extension structure, roof and glazing
- Drainage and water supply positioned for the sink and appliances
How long does it take?
Allow 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 South Glamorgan
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
Towns we cover in South Glamorgan include Cardiff, Barry and Penarth.
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
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about kitchen extensions in South Glamorgan
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 long does a kitchen extension take in South Glamorgan?
Typically 11 to 16 weeks on site, including kitchen fitting. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a kitchen extension cost in South Glamorgan?
In South Glamorgan, a kitchen extension typically costs £2,050–£3,150 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £45,000–£69,500. Your fixed price depends on the survey and drawings.
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.
Do I need planning permission for a kitchen extension in South Glamorgan?
In Wales a single-storey rear extension is often permitted development: up to 4 metres beyond the rear wall and up to 4 metres high, with eaves no higher than 3 metres within 2 metres of a boundary and no more than half the land around the original house covered. Wales has no larger home extension prior approval route, so deeper extensions need a planning application, as do extensions to flats, listed buildings and houses whose rights have been removed.
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.
