Kitchen extensions with bedrooms above in Thornaby-on-Tees
For a kitchen extension with bedrooms above in Thornaby-on-Tees, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for County Durham.
Quick reference for homeowners in Thornaby-on-Tees.
- Postcode districts
- TS17
- County / area
- County Durham, England
- Price region
- North East England
- Guide price
- £50,500–£68,000 (£1,800–£2,430 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
- Stockton-on-Tees (2.5 miles), Yarm (3.1 miles), Billingham (3.9 miles)
- Distance to Darlington
- about 10.1 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.
Thornaby-on-Tees sits about 10.1 miles from Darlington. Closer to home, Stockton-on-Tees is 2.5 miles away and Yarm 3.1 miles.
What it costs in Thornaby-on-Tees
Expect a kitchen extension with bedrooms above in Thornaby-on-Tees to land somewhere around £50,500–£68,000 (kitchen units and worktops priced separately) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Our North East England guide rate is £1,800–£2,430 per m², including VAT. Professional fees for drawings and the structural engineer are listed separately on our prices page.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,660–£2,240 per m² | £46,500–£62,500 |
| Standard | £1,800–£2,430 per m² | £50,500–£68,000 |
| Premium | £2,160–£2,920 per m² | £60,500–£81,500 |
Planning and building regulations in Thornaby-on-Tees
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 Thornaby-on-Tees 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 Thornaby-on-Tees 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, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.
Questions about kitchen extensions with bedrooms above in Thornaby-on-Tees
Which postcodes do you cover around Thornaby-on-Tees?
We cover Thornaby-on-Tees (TS17) and nearby places including Stockton-on-Tees, Yarm and Billingham, plus the rest of County Durham. The first site visit is free.
Who handles building regulations for a project in Thornaby-on-Tees?
We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
Do I need planning permission for a kitchen extension with bedrooms above in Thornaby-on-Tees?
Thornaby-on-Tees 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
Close to Thornaby-on-Tees? We work across the area, including:
Other extensions in Thornaby-on-Tees
All two-storey extension services in Thornaby-on-Tees · Kitchen extensions with bedrooms above across County Durham
Tell us about your house in Thornaby-on-Tees and we'll call you back to arrange a free, no-obligation visit.