Two-storey extensions in Seaford
From over-garage bedrooms to full wraparounds, we cover every kind of two-storey extension in Seaford.
Seaford at a glance
- Postcode districts
- BN25
- Area
- East Sussex, England
- Price region
- South East England
- Nearest towns
- Newhaven (2.7 miles), Peacehaven (5 miles), Rottingdean (7.6 miles), Eastbourne (7.9 miles)
- Distance to Brighton
- about 11.3 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 postcode district BN25 in and around Seaford, along with neighbouring Newhaven, Peacehaven and Rottingdean.
Extensions available in Seaford
Two-storey rear extensions
Design, approvals and build for Seaford homes. Guide from £61,500.
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Two-storey side extensions
Our South East England guide starts at £94,500 for this type.
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Two-storey wraparound extensions
Seaford guide price from £132,500, Standard spec.
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Part single, part two-storey extensions
Seaford guide price from £79,000, Standard spec.
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Extensions over a garage
Design, approvals and build for Seaford homes. Guide from £34,500.
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First-floor extensions
For homes in Seaford: typical guide from £27,500.
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Two-storey extensions for semi-detached houses
Guide from £61,500 in Seaford, including VAT.
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Two-storey extensions for detached houses
Design, approvals and build for Seaford homes. Guide from £94,500.
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Kitchen extensions with bedrooms above
From £61,500 (before kitchen units) in Seaford. Free visit to firm it up.
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Extra bedroom and en-suite extensions
For homes in Seaford: typical guide from £61,500 (plus en-suite).
Learn moreWhich type suits your house?
Rear, side, wraparound or over the garage: each adds space in a different way. For most houses in East Sussex, one or two of these will clearly suit the plot better than the rest, and we'll tell you which.
Also available in East Sussex
- 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 Seaford
Seaford 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 Seaford
Do you cover Seaford?
Yes. We cover Seaford (BN25) and the surrounding area, including Newhaven and Peacehaven. The first site visit is free.
What does a two-storey extension cost in Seaford?
Using our South 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 £61,500–£83,000 including VAT. An extension over a garage is about £34,500–£50,500.
Which other places near Seaford do you cover?
Everywhere around it, including Newhaven (2.7 miles), Peacehaven (5 miles) and Rottingdean (7.6 miles), and the rest of East Sussex.