Two-storey extensions in Carshalton
Need more room in Carshalton? Two-storey and first-floor extensions add bedrooms and living space without moving. Here's everything we offer locally.
Carshalton at a glance
- Postcode districts
- SM1 and SM5
- Area
- Greater London, England
- Price region
- London
- Nearest towns
- Wallington (0.7 miles), St Helier (1.2 miles), Sutton (1.9 miles), Belmont (Greater London) (2.2 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 Carshalton (SM1 and SM5) and the places around it, including Wallington (0.7 miles), St Helier (1.2 miles) and Sutton.
Extensions available in Carshalton
Two-storey rear extensions
Carshalton guide price from £67,000, Standard spec.
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Two-storey side extensions
Our London guide starts at £103,500 for this type.
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Two-storey wraparound extensions
Guide from £144,500 in Carshalton, including VAT.
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Part single, part two-storey extensions
Carshalton guide price from £86,500, Standard spec.
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Extensions over a garage
For homes in Carshalton: typical guide from £38,000.
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First-floor extensions
Our London guide starts at £30,000 for this type.
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Two-storey extensions for semi-detached houses
Design, approvals and build for Carshalton homes. Guide from £67,000.
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Two-storey extensions for detached houses
From £103,500 in Carshalton. Free visit to firm it up.
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Kitchen extensions with bedrooms above
Design, approvals and build for Carshalton homes. Guide from £67,000 (before kitchen units).
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Extra bedroom and en-suite extensions
Carshalton guide price from £67,000 (plus en-suite), Standard spec.
Learn moreWhich type suits your house?
Which type suits your house in Carshalton 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 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 Carshalton
Carshalton 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 Carshalton
Do you cover Carshalton?
Yes. We cover Carshalton (SM1 and SM5) and the surrounding area, including Wallington and St Helier. The first site visit is free.
What does a two-storey extension cost in Carshalton?
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 Carshalton do you cover?
Everywhere around it, including Wallington (0.7 miles), St Helier (1.2 miles) and Sutton (1.9 miles), and the rest of Greater London.