Two-storey extensions in London Colney
Homeowners in London Colney can use us for the whole project or just the drawings and approvals. Start with a free visit.
London Colney at a glance
- Postcode districts
- AL2
- Area
- Hertfordshire, England
- Price region
- East of England
- Nearest towns
- St Albans (2.4 miles), Hatfield (4.1 miles), Borehamwood (4.9 miles), North Watford (5.2 miles)
- Distance to Watford
- about 6.4 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.
Around London Colney we also work in St Albans, Hatfield and Borehamwood, and across the rest of Hertfordshire. Postcode district in and near London Colney: AL2.
Extensions available in London Colney
Two-storey rear extensions
London Colney guide price from £57,500, Standard spec.
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Two-storey side extensions
Guide from £88,500 in London Colney, including VAT.
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Two-storey wraparound extensions
Design, approvals and build for London Colney homes. Guide from £124,000.
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Part single, part two-storey extensions
For homes in London Colney: typical guide from £74,000.
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Extensions over a garage
Our East of England guide starts at £32,500 for this type.
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First-floor extensions
From £26,000 in London Colney. Free visit to firm it up.
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Two-storey extensions for semi-detached houses
London Colney guide price from £57,500, Standard spec.
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Two-storey extensions for detached houses
Design, approvals and build for London Colney homes. Guide from £88,500.
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Kitchen extensions with bedrooms above
Guide from £57,500 (before kitchen units) in London Colney, including VAT.
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Extra bedroom and en-suite extensions
Design, approvals and build for London Colney homes. Guide from £57,500 (plus en-suite).
Learn moreWhich type suits your house?
The boundaries usually decide it. Two-storey work close to a neighbour needs careful design for light and privacy, so at the visit in London Colney we measure distances to every boundary before suggesting a type.
Also available in Hertfordshire
- 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 London Colney
London Colney 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 London Colney
Do you cover London Colney?
Yes. We cover London Colney (AL2) and the surrounding area, including St Albans and Hatfield. The first site visit is free.
What does a two-storey extension cost in London Colney?
Using our East of 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 London Colney do you cover?
Everywhere around it, including St Albans (2.4 miles), Hatfield (4.1 miles) and Borehamwood (4.9 miles), and the rest of Hertfordshire.