Two-storey extensions in Horsham
Planning a bigger home in Horsham? Compare extension types and guide prices below, then book a free site visit.
Horsham at a glance
- Postcode districts
- RH12, RH13 and RH14
- Area
- West Sussex, England
- Price region
- South East England
- Nearest towns
- Broadfield (5.8 miles), Crawley (7.2 miles), Cranleigh (8.7 miles), Horley (10.6 miles)
- Distance to Crawley
- about 7.2 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.
Around Horsham we also work in Broadfield, Crawley and Cranleigh, and across the rest of West Sussex. Postcode districts in and near Horsham: RH12, RH13 and RH14.
Extensions available in Horsham
Two-storey rear extensions
Design, approvals and build for Horsham homes. Guide from £61,500.
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Two-storey side extensions
For homes in Horsham: typical guide from £94,500.
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Two-storey wraparound extensions
Design, approvals and build for Horsham homes. Guide from £132,500.
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Part single, part two-storey extensions
Design, approvals and build for Horsham homes. Guide from £79,000.
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Extensions over a garage
Design, approvals and build for Horsham homes. Guide from £34,500.
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First-floor extensions
Design, approvals and build for Horsham homes. Guide from £27,500.
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Two-storey extensions for semi-detached houses
From £61,500 in Horsham. Free visit to firm it up.
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Two-storey extensions for detached houses
Guide from £94,500 in Horsham, including VAT.
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Kitchen extensions with bedrooms above
For homes in Horsham: typical guide from £61,500 (before kitchen units).
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Extra bedroom and en-suite extensions
Horsham guide price from £61,500 (plus en-suite), Standard spec.
Learn moreWhich type suits your house?
If you're not sure which type fits, that's what the free visit is for. We'll sketch the realistic options for your house in Horsham, with a rough idea of the approval route and cost for each.
Also available in West Sussex
- 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 Horsham
Horsham 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 Horsham
Do you cover Horsham?
Yes. We cover Horsham (RH12, RH13 and RH14) and the surrounding area, including Broadfield and Crawley. The first site visit is free.
What does a two-storey extension cost in Horsham?
Using our South East 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 £61,500–£83,000 including VAT. An extension over a garage is about £34,500–£50,500.
Which other places near Horsham do you cover?
Everywhere around it, including Broadfield (5.8 miles), Crawley (7.2 miles) and Cranleigh (8.7 miles), and the rest of West Sussex.