Extensions over a garage in Seaham
A over-garage extension in Seaham starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in SeahamFrom £21,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsSR7
Do I need planning permission in Seaham?
In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.
The planning position for a specific Seaham address depends on its history and any designations, which is why we check it at the first visit.
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
Site visits are available across Seaham (SR7). The same team covers Peterlee (5 miles), Chester-le-Street (9 miles), Durham (10 miles), Hartlepool (12 miles), all within easy reach.
Just over the Tyne and Wear border, Houghton-le-Spring is about 5 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.
Guide prices for 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: £1,640 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £21,500 – £27,000 | £22,500 – £29,500 | £29,000 – £37,500 |
| Over a large single garage 16 m² | £26,000 – £32,500 | £30,500 – £39,500 | £39,000 – £50,000 |
| Over a double garage 24 m² | £39,000 – £48,500 | £45,500 – £59,000 | £58,500 – £74,500 |
Try the guide-price tool to see a range for your own size and finish.
What is included
- Insulation, electrics, heating and finish
- Design and householder planning application
- Opening into the existing first floor
- Structural survey of garage walls and foundations
Fitting the new room to the existing landing is the planning puzzle inside the house. We design the connection first, then the roof, so the extension does not end up with awkward steps or a corridor through a 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 Seaham home, measure up, talk through what you want and check the planning position.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Seaham
Who do I contract with for an over-garage 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 you cover all of Seaham?
Yes. We cover Seaham and the surrounding parts of County Durham. Site visits are free and there is no obligation.
Will my neighbours in Seaham 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.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
Can my garage take the weight of a room on top?
Some can and some cannot. Many garages have a single-skin wall or shallow foundations. Our structural engineer checks this before we give a fixed price.
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.