Kitchen extensions with bedrooms above in Trowbridge
Homes in Trowbridge with a bit of space to the side or rear can often take a kitchen extension with bedrooms above. We'll tell you honestly whether yours can, and what approvals it needs.
What we'd confirm first for a project in Trowbridge.
- Postcode districts
- BA14 and BA15
- County / area
- Wiltshire, England
- Price region
- South West England
- Guide price
- £57,500–£78,000 (£2,060–£2,780 per m²), kitchen units and worktops priced separately
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
- Nearest towns
- Westbury (4.2 miles), Melksham (4.8 miles), Neston (Wiltshire) (6.5 miles)
- Distance to Swindon
- about 24.7 miles
- First visit
- Free, no obligation
About a kitchen extension with bedrooms above
This service suits you if your kitchen is too small and you also need another bedroom. Building both floors at once costs less than a single-storey kitchen extension now and a first floor later. You get a layout that works for cooking, eating and the garden, a bedroom plan that works upstairs, the approvals your nation needs and the build, carried out by vetted teams working under S&K. Kitchen units are priced separately.
We cover postcode districts BA14 and BA15 in and around Trowbridge, along with neighbouring Westbury, Melksham and Neston (Wiltshire).
What it costs in Trowbridge
A guide price for Trowbridge: around £57,500–£78,000 (kitchen units and worktops priced separately) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £2,060–£2,780 per m² of new floor space, including VAT at 20%. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,900–£2,560 per m² | £53,000–£71,500 |
| Standard | £2,060–£2,780 per m² | £57,500–£78,000 |
| Premium | £2,470–£3,340 per m² | £69,000–£93,500 |
Planning and building regulations in Trowbridge
In England, a two-storey rear kitchen extension can be permitted development if it goes no more than 3 m beyond the rear wall of the original house and stays at least 7 m from the rear boundary, with matching materials and roof pitch, outside protected areas. No balconies are allowed. Deeper designs need planning permission, costing £548 (or £575 for applications made from 8 December 2026).
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Trowbridge homes
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.
Glazing and the Part L 25% rule
In England, new windows, roof lights and glazed doors in an extension are normally limited to 25% of the extension's floor area plus the area of any windows or doors removed. Larger glazing is possible, but needs SAP or compensating calculations, so we plan the rear doors around this from the start.
How we'd run your project
Measure and listen
A visit to Trowbridge to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Trowbridge.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about kitchen extensions with bedrooms above in Trowbridge
Which postcodes do you cover around Trowbridge?
We cover Trowbridge (BA14 and BA15) and nearby places including Westbury, Melksham and Neston (Wiltshire), plus the rest of Wiltshire. The first site visit is free.
How much does a kitchen extension with bedrooms above cost in Trowbridge?
Our guide for South West England, which covers Trowbridge, is £2,060–£2,780 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 £57,500–£78,000 (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.
Do I need planning permission for a kitchen extension with bedrooms above in Trowbridge?
Trowbridge is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
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.
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.
Nearby
Other towns near Trowbridge:
Other extensions in Trowbridge
All two-storey extension services in Trowbridge · Kitchen extensions with bedrooms above across Wiltshire
Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.