Single-storey rear extensions in Seaham
Planning a single-storey extension in Seaham? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in SeahamFrom £19,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsSR7
Covering Seaham
Site visits are available across Seaham (SR7). We also work in nearby Peterlee (5 miles), Chester-le-Street (9 miles), Durham (10 miles), Hartlepool (12 miles).
For homes towards Tyne and Wear, Houghton-le-Spring is around 5 miles away. Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
Planning rules that apply in Seaham
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
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.
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).
What should I budget for a single-storey extension in Seaham?
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 Seaham: £1,590 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,000 – £22,500 | £22,000 – £28,500 | £28,000 – £37,500 |
| 4 m × 5 m 20 m² | £31,500 – £37,500 | £37,000 – £47,500 | £47,000 – £62,000 |
| 5 m × 6 m 30 m² | £47,500 – £56,000 | £55,500 – £71,000 | £70,500 – £93,000 |
Try the guide-price tool to see a range for your own size and finish.
What we take care of
- Planning route checked and the right approval obtained
- Building regulations drawings and structural calculations
- Foundations, drainage and groundworks
- Flat or pitched roof, rooflights or lantern
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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 single-storey extension in Seaham
Who do I contract with for a single-storey 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.
How long does a single-storey extension take to build in Seaham?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
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.