Two-storey extensions in King's Cross
Need more room in King's Cross? Two-storey and first-floor extensions add bedrooms and living space without moving. Here's everything we offer locally.
King's Cross at a glance
- Postcode districts
- N1C, WC1H and WC1X
- Area
- Greater London, England
- Price region
- London
- Nearest towns
- Barnsbury (0.7 miles), Holborn (0.9 miles), Islington (0.9 miles), Camden Town (1.1 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 King's Cross we also work in Barnsbury, Holborn and Islington, and across the rest of Greater London. Postcode districts in and near King's Cross: N1C, WC1H and WC1X.
Extensions available in King's Cross
Two-storey rear extensions
Guide from £67,000 in King's Cross, including VAT.
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Two-storey side extensions
King's Cross guide price from £103,500, Standard spec.
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Two-storey wraparound extensions
Guide from £144,500 in King's Cross, including VAT.
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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
For homes in King's Cross: 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
Guide from £67,000 in King's Cross, including VAT.
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Two-storey extensions for detached houses
Design, approvals and build for King's Cross homes. Guide from £103,500.
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Kitchen extensions with bedrooms above
For homes in King's Cross: typical guide from £67,000 (before kitchen units).
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Extra bedroom and en-suite extensions
From £67,000 (plus en-suite) in King's Cross. Free visit to firm it up.
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 King's Cross
King's Cross 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 King's Cross
Do you cover King's Cross?
Yes. We cover King's Cross (N1C, WC1H and WC1X) and the surrounding area, including Barnsbury and Holborn. The first site visit is free.
What does a two-storey extension cost in King's Cross?
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 King's Cross do you cover?
Everywhere around it, including Barnsbury (0.7 miles), Holborn (0.9 miles) and Islington (0.9 miles), and the rest of Greater London.