Kitchen extensions with bedrooms above in Thornhill
Thinking about a kitchen extension with bedrooms above in Thornhill? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.
Quick reference for homeowners in Thornhill.
- Postcode districts
- CF3 and CF23
- County / area
- Cardiff and the Vale of Glamorgan, Wales
- Price region
- Wales
- Guide price
- £51,500–£69,500 (£1,840–£2,480 per m²), kitchen units and worktops priced separately
- Approval route
- It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
- Nearest towns
- Rhiwbina (1.3 miles), Whitchurch (Cardiff and the Vale of Glamorgan) (2.4 miles), Caerphilly (2.5 miles)
- Distance to Cardiff
- about 4.3 miles
- First visit
- Free, no obligation
About a kitchen extension with bedrooms above
A kitchen extension with bedrooms above is a two-storey extension designed so the ground floor becomes a larger, usually open-plan kitchen and dining space, with one or two bedrooms or a bathroom on the first floor. It is a natural fit for a two-storey rear extension. The key design issues are the steel beams that open up the house, glazing and ventilation.
We cover postcode districts CF3 and CF23 in and around Thornhill, along with neighbouring Rhiwbina, Whitchurch (Cardiff and the Vale of Glamorgan) and Caerphilly.
What it costs in Thornhill
Guide prices for kitchen extensions with bedrooms above in Wales are around £1,840–£2,480 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £51,500–£69,500 (kitchen units and worktops priced separately). Design fees, structural calculations and approval fees are separate and listed on our prices page.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,690–£2,290 per m² | £47,500–£64,000 |
| Standard | £1,840–£2,480 per m² | £51,500–£69,500 |
| Premium | £2,210–£2,980 per m² | £62,000–£83,500 |
Planning and building regulations in Thornhill
In Wales, a kitchen extension with bedrooms above can be permitted development if the kitchen goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. This lets the kitchen project further than the bedrooms. Otherwise a householder application costs £585.
Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).
Design points for Thornhill homes
Services and drainage
Sinks, dishwashers and an upstairs bathroom all need waste routes to the drains, often near where the extension goes. We check the drains early and plan soil stacks, gas and electrical supplies so the kitchen layout is not limited later.
Steel beams and the open-plan opening
Removing the old rear wall to make one large room means a steel beam, sometimes several, to carry the first floor and roof. The engineer sizes the steel and its supports, and we decide early whether you want a flush ceiling with the beam hidden or a downstand, as this affects ceiling heights.
How we'd run your project
Look at the house
We start in Thornhill with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.
Questions about kitchen extensions with bedrooms above in Thornhill
How long does a kitchen extension with bedrooms above take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
Who handles building regulations for a project in Thornhill?
We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How much does a kitchen extension with bedrooms above cost in Thornhill?
Our guide for Wales, which covers Thornhill, is £1,840–£2,480 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £51,500–£69,500 (kitchen units and worktops priced separately). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Can I keep using my kitchen during the build?
For part of it. The new structure can be built while your existing kitchen stays in use, but when the rear wall is opened and the new kitchen is fitted there will be several weeks without one. We plan when this happens and help you set up a temporary kitchen elsewhere in the house.
Is it cheaper to build a kitchen extension and bedrooms at the same time?
Yes, in most cases. Building both floors at once means one set of foundations, one roof, one scaffold and one set of approvals. Adding a first floor later means removing the original roof, possibly strengthening the foundations and disrupting the kitchen again. If you think you will need the bedroom, build it now.
Nearby
The same service in neighbouring towns:
Other extensions in Thornhill
All two-storey extension services in Thornhill · Kitchen extensions with bedrooms above across Cardiff and the Vale of Glamorgan
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Thornhill.