Two-storey extensions in Barnham
Everything for a two-storey extension in Barnham, in one place: types, guide prices for South East England, the approval rules in England and how to get started.
Barnham at a glance
- Postcode districts
- BN18
- Area
- West Sussex, England
- Price region
- South East England
- Nearest towns
- Westergate (1.6 miles), Bognor Regis (3.9 miles), Littlehampton (4.5 miles), Rustington (5.9 miles)
- Distance to Crawley
- about 27.8 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 Barnham (BN18) and the places around it, including Westergate (1.6 miles), Bognor Regis (3.9 miles) and Littlehampton.
Extensions available in Barnham
Two-storey rear extensions
From £61,500 in Barnham. Free visit to firm it up.
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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
Design, approvals and build for Barnham homes. Guide from £132,500.
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Part single, part two-storey extensions
Design, approvals and build for Barnham homes. Guide from £79,000.
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Extensions over a garage
Design, approvals and build for Barnham homes. Guide from £34,500.
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First-floor extensions
For homes in Barnham: typical guide from £27,500.
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Two-storey extensions for semi-detached houses
Our South East England guide starts at £61,500 for this type.
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Two-storey extensions for detached houses
Design, approvals and build for Barnham homes. Guide from £94,500.
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Kitchen extensions with bedrooms above
Barnham guide price from £61,500 (before kitchen units), Standard spec.
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Extra bedroom and en-suite extensions
For homes in Barnham: typical guide from £61,500 (plus en-suite).
Learn moreWhich type suits your house?
Which type suits your house in Barnham depends mostly on where you have room. A deep garden points to a rear extension; space beside the house points to a side or over-garage extension; a house that already has a single-storey extension can often take a first floor on top.
Also available in West 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 Barnham
Barnham 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 Barnham
Do you cover Barnham?
Yes. We cover Barnham (BN18) and the surrounding area, including Westergate and Bognor Regis. The first site visit is free.
What does a two-storey extension cost in Barnham?
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 Barnham do you cover?
Everywhere around it, including Westergate (1.6 miles), Bognor Regis (3.9 miles) and Littlehampton (4.5 miles), and the rest of West Sussex.