Bedroom extensions in Thornaby-on-Tees
Thornaby-on-Tees homeowners can use us for the whole bedroom extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in Thornaby-on-TeesFrom £23,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsTS17
Planning and approvals in Thornaby-on-Tees
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Local to Thornaby-on-Tees
Postcode districts we cover around Thornaby-on-Tees include TS17. The same team covers Stockton-on-Tees (3 miles), Yarm (3 miles), Billingham (4 miles), Darlington (10 miles), all within easy reach.
Just over the North Yorkshire border, Middlesbrough is about 4 miles away. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
How much does a bedroom extension cost in Thornaby-on-Tees?
These guide figures apply our North East England adjustment (×0.91) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Thornaby-on-Tees: £1,460 to £2,910 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £23,500 – £29,000 | £23,500 – £31,000 | £26,000 – £35,000 |
| Bedroom and en-suite 18 m² | £26,000 – £32,000 | £31,000 – £40,500 | £39,000 – £52,500 |
| Two rooms 30 m² | £43,500 – £53,500 | £51,500 – £67,000 | £65,500 – £87,500 |
Try the guide-price tool to see a range for your own size and finish.
When a bedroom extension makes sense
- Growing families
- Multi-generational households
- Homeowners who want an en-suite master bedroom
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Thornaby-on-Tees
Will my neighbours in Thornaby-on-Tees be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do I need building regulations approval in Thornaby-on-Tees?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Who do I contract with for a bedroom extension in Thornaby-on-Tees?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How much does a bedroom extension cost?
Our guide range is about £1,460 to £2,910 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £31,000 to £40,500 at standard spec, depending on whether it is part of a larger two-storey build.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
Book a free site visit in Thornaby-on-Tees
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.