Bedroom extensions in Seaham
Our design and build teams take on bedroom extensions in Seaham, from the first measured survey through planning and building control to the finished room.
- Guide price in SeahamFrom £23,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSR7
Will the council need to approve it?
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 regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
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).
Working in Seaham
We cover Seaham and the postcode districts SR7. Nearby, we also take on projects in Peterlee (5 miles), Chester-le-Street (9 miles), Durham (10 miles), Hartlepool (12 miles).
Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
What is included
- Heating extended to the new rooms
- Layout options: two-storey, over-garage or ground floor
- Planning drawings and application
- Structure, roof, insulation and finish
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
What should I budget for a bedroom extension in Seaham?
Labour and material costs vary across the UK, so for Seaham we use our North East England factor (×0.91). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Seaham: £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.
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
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 Seaham
How long does a bedroom extension take to build in Seaham?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Who do I contract with for a bedroom extension in Seaham?
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.
Do I need building regulations approval in Seaham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
Book a free site visit in Seaham
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.