Two-storey extensions in Seaham
We design, get approval for and build two-storey extensions in Seaham and the surrounding area. Choose the type of extension below or book a free site visit.
Seaham at a glance
- Postcode districts
- SR7
- Area
- County Durham, England
- Price region
- North East England
- Nearest towns
- Ryhope (2.4 miles), Hetton-le-Hole (4.4 miles), Houghton-le-Spring (4.7 miles), Sunderland (4.8 miles)
- Distance to Darlington
- about 23.2 miles
- Approvals
- Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission.
We cover Seaham (SR7) and the places around it, including Ryhope (2.4 miles), Hetton-le-Hole (4.4 miles) and Houghton-le-Spring.
Extensions available in Seaham
Two-storey rear extensions
Our North East England guide starts at £50,500 for this type.
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Two-storey side extensions
From £77,500 in Seaham. Free visit to firm it up.
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Two-storey wraparound extensions
Seaham guide price from £108,500, Standard spec.
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Part single, part two-storey extensions
Our North East England guide starts at £65,000 for this type.
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Extensions over a garage
Guide from £28,500 in Seaham, including VAT.
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First-floor extensions
From £22,500 in Seaham. Free visit to firm it up.
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Two-storey extensions for semi-detached houses
Design, approvals and build for Seaham homes. Guide from £50,500.
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Two-storey extensions for detached houses
Seaham guide price from £77,500, Standard spec.
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Kitchen extensions with bedrooms above
Guide from £50,500 (before kitchen units) in Seaham, including VAT.
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Extra bedroom and en-suite extensions
Design, approvals and build for Seaham homes. Guide from £50,500 (plus en-suite).
Learn moreWhich type suits your house?
The boundaries usually decide it. Two-storey work close to a neighbour needs careful design for light and privacy, so at the visit in Seaham we measure distances to every boundary before suggesting a type.
Also available in County Durham
- Two-storey front extensions
- Two-storey extensions for end-of-terrace houses
- Two-storey annexe extensions
- Garage conversions with a room above
- Two-storey extension plans and drawings
- Planning permission for two-storey extensions
- Structural engineering for two-storey extensions
- Building regulations for two-storey extensions
- Party wall notices for extensions
- Design and build two-storey extensions
Rules for Seaham
Seaham is in England. Two-storey rear: up to 3 m deep and 7 m from the rear boundary under permitted development. Side, wraparound and front: planning permission. Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
The full England rules explained
Questions about extensions in Seaham
Do you cover Seaham?
Yes. We cover Seaham (SR7) and the surrounding area, including Ryhope and Hetton-le-Hole. The first site visit is free.
What does a two-storey extension cost in Seaham?
Using our North East England guide, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) is about £50,500–£68,000 including VAT. An extension over a garage is about £28,500–£41,500.
Which other places near Seaham do you cover?
Everywhere around it, including Ryhope (2.4 miles), Hetton-le-Hole (4.4 miles) and Houghton-le-Spring (4.7 miles), and the rest of County Durham.