Two-storey extensions in Belsize Park
Everything for a two-storey extension in Belsize Park, in one place: types, guide prices for London, the approval rules in England and how to get started.
Belsize Park at a glance
- Postcode districts
- NW3
- Area
- Greater London, England
- Price region
- London
- Nearest towns
- Hampstead (0.6 miles), Kilburn (0.9 miles), Chalk Farm (1 mile), Camden Town (1.3 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 NW3 in and around Belsize Park, along with neighbouring Hampstead, Kilburn and Chalk Farm.
Extensions available in Belsize Park
Two-storey rear extensions
Belsize Park guide price from £67,000, Standard spec.
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Two-storey side extensions
Guide from £103,500 in Belsize Park, including VAT.
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Two-storey wraparound extensions
From £144,500 in Belsize Park. Free visit to firm it up.
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Part single, part two-storey extensions
Design, approvals and build for Belsize Park homes. Guide from £86,500.
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Extensions over a garage
For homes in Belsize Park: typical guide from £38,000.
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First-floor extensions
Design, approvals and build for Belsize Park homes. Guide from £30,000.
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Two-storey extensions for semi-detached houses
From £67,000 in Belsize Park. Free visit to firm it up.
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Two-storey extensions for detached houses
Design, approvals and build for Belsize Park homes. Guide from £103,500.
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Kitchen extensions with bedrooms above
Belsize Park guide price from £67,000 (before kitchen units), Standard spec.
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Extra bedroom and en-suite extensions
Our London guide starts at £67,000 (plus en-suite) for this type.
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 Belsize Park
Belsize Park 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 Belsize Park
Do you cover Belsize Park?
Yes. We cover Belsize Park (NW3) and the surrounding area, including Hampstead and Kilburn. The first site visit is free.
What does a two-storey extension cost in Belsize Park?
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 Belsize Park do you cover?
Everywhere around it, including Hampstead (0.6 miles), Kilburn (0.9 miles) and Chalk Farm (1 mile), and the rest of Greater London.