Side extensions across Seaham
From the first sketch to final sign-off, we plan and build side extensions in Seaham and the surrounding County Durham area.
- Guide price in SeahamFrom £20,000 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsSR7
Working in Seaham
Postcode districts we cover around Seaham include SR7. We also work in nearby Peterlee (5 miles), Chester-le-Street (9 miles), Durham (10 miles), Hartlepool (12 miles).
Just over the Tyne and Wear border, Houghton-le-Spring is about 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.
Do I need planning permission in Seaham?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Included in a typical project
- Planning route checked or application made
- Foundations near boundaries and any drains
- Survey, design and street-view drawings
- Windows, doors and finishes to match
- Structure, roof tied into the house
- New openings through the side wall
Side extension prices in Seaham
Prices below are for Seaham, using the North East England factor of ×0.91. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Seaham: £1,590 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £20,000 – £24,500 | £22,000 – £29,000 | £28,000 – £37,500 |
| 3 m × 6 m 18 m² | £28,500 – £34,500 | £33,500 – £43,500 | £42,500 – £56,000 |
| 3 m × 8 m 24 m² | £38,000 – £46,000 | £44,500 – £58,000 | £56,500 – £74,500 |
For a figure based on your own dimensions, use our guide-price tool.
How the project works
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
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.
Questions people ask about side extensions
Who do I contract with for a side 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Seaham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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 build over my driveway?
Yes, if the foundations work and you keep any parking the council requires. Drains and services under drives are common, so we check before design.
How much does a side extension cost?
Our guide range is about £1,590 to £3,090 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £33,500 to £43,500 in Seaham.
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.