Two-storey extensions in Keynsham
Planning a bigger home in Keynsham? Compare extension types and guide prices below, then book a free site visit.
Keynsham at a glance
- Postcode districts
- BS31
- Area
- Somerset, England
- Price region
- South West England
- Nearest towns
- Kingswood (2.7 miles), Whitchurch (Bristol) (2.8 miles), Publow (3.1 miles), Mangotsfield (5.1 miles)
- Distance to Bath
- about 6.5 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.
Around Keynsham we also work in Kingswood, Whitchurch (Bristol) and Publow, and across the rest of Somerset. Postcode district in and near Keynsham: BS31.
Extensions available in Keynsham
Two-storey rear extensions
Keynsham guide price from £57,500, Standard spec.
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Two-storey side extensions
From £88,500 in Keynsham. Free visit to firm it up.
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Two-storey wraparound extensions
Design, approvals and build for Keynsham homes. Guide from £124,000.
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Part single, part two-storey extensions
Design, approvals and build for Keynsham homes. Guide from £74,000.
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Extensions over a garage
For homes in Keynsham: typical guide from £32,500.
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First-floor extensions
Design, approvals and build for Keynsham homes. Guide from £26,000.
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Two-storey extensions for semi-detached houses
Our South West England guide starts at £57,500 for this type.
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Two-storey extensions for detached houses
Design, approvals and build for Keynsham homes. Guide from £88,500.
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Kitchen extensions with bedrooms above
From £57,500 (before kitchen units) in Keynsham. Free visit to firm it up.
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Extra bedroom and en-suite extensions
For homes in Keynsham: typical guide from £57,500 (plus en-suite).
Learn moreWhich type suits your house?
Start with what you need the space for. Bedrooms and an en-suite upstairs with a bigger kitchen below is the classic two-storey brief, but in Keynsham we also design annexes, home offices and bedrooms over garages.
Also available in Somerset
- 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 Keynsham
Keynsham 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 Keynsham
Do you cover Keynsham?
Yes. We cover Keynsham (BS31) and the surrounding area, including Kingswood and Whitchurch (Bristol). The first site visit is free.
What does a two-storey extension cost in Keynsham?
Using our South West 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 £57,500–£78,000 including VAT. An extension over a garage is about £32,500–£47,500.
Which other places near Keynsham do you cover?
Everywhere around it, including Kingswood (2.7 miles), Whitchurch (Bristol) (2.8 miles) and Publow (3.1 miles), and the rest of Somerset.