Two-storey extensions in Chelsea
We design, get approval for and build two-storey extensions in Chelsea and the surrounding area. Choose the type of extension below or book a free site visit.
Chelsea at a glance
- Postcode districts
- SW3, SW7 and SW10
- Area
- Greater London, England
- Price region
- London
- Nearest towns
- Battersea (1.1 miles), Knightsbridge and Belgravia (1.2 miles), Earls Court (1.3 miles), Fulham (1.4 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 districts SW3, SW7 and SW10 in and around Chelsea, along with neighbouring Battersea, Knightsbridge and Belgravia and Earls Court.
Extensions available in Chelsea
Two-storey rear extensions
Design, approvals and build for Chelsea homes. Guide from £67,000.
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Two-storey side extensions
Chelsea guide price from £103,500, Standard spec.
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Two-storey wraparound extensions
Our London guide starts at £144,500 for this type.
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Part single, part two-storey extensions
Our London guide starts at £86,500 for this type.
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Extensions over a garage
Chelsea guide price from £38,000, Standard spec.
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First-floor extensions
Guide from £30,000 in Chelsea, including VAT.
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Two-storey extensions for semi-detached houses
For homes in Chelsea: typical guide from £67,000.
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Two-storey extensions for detached houses
From £103,500 in Chelsea. Free visit to firm it up.
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Kitchen extensions with bedrooms above
For homes in Chelsea: typical guide from £67,000 (before kitchen units).
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Extra bedroom and en-suite extensions
For homes in Chelsea: typical guide from £67,000 (plus en-suite).
Learn moreWhich type suits your house?
Rear and side extensions suit most semi-detached and detached houses with room around them. Terraced and town-centre homes can take a two-storey extension too, with more care over neighbours, light and access.
Also available in Greater London
- 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 Chelsea
Chelsea 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 Chelsea
Do you cover Chelsea?
Yes. We cover Chelsea (SW3, SW7 and SW10) and the surrounding area, including Battersea and Knightsbridge and Belgravia. The first site visit is free.
What does a two-storey extension cost in Chelsea?
Using our London 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 £67,000–£90,500 including VAT. An extension over a garage is about £38,000–£55,000.
Which other places near Chelsea do you cover?
Everywhere around it, including Battersea (1.1 miles), Knightsbridge and Belgravia (1.2 miles) and Earls Court (1.3 miles), and the rest of Greater London.