Bedroom extensions in Darlington
Thinking about a bedroom extension for your Darlington home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in DarlingtonFrom £23,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsDL1, DL2, DL3
Extensions in and around Darlington
We cover Darlington and the postcode districts DL1, DL2, DL3. The same team covers Newton Aycliffe (7 miles), Yarm (8 miles), Stockton-on-Tees (10 miles), Thornaby-on-Tees (10 miles), all within easy reach.
For homes towards North Yorkshire, Middlesbrough is around 13 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.
Do I need planning permission in Darlington?
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
What should I budget for a bedroom extension in Darlington?
For Darlington we adjust our national guide rates by ×0.91, the factor we use for North East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Darlington: £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 |
For a figure based on your own dimensions, use our guide-price tool.
Who a bedroom extension suits
- 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
We visit your Darlington home, measure up, talk through what you want and check the planning position.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a bedroom extension in Darlington
Do you cover all of Darlington?
Yes. We cover Darlington and the surrounding parts of County Durham. Site visits are free and there is no obligation.
How long does a bedroom extension take to build in Darlington?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Darlington, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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 Darlington
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.