House extensions in Crawley
Looking to extend your home in Crawley? Start here: extension types, guide prices for Crawley, the planning rules that apply and how a project runs.
- Postcode districtsRH10, RH11
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Crawley home?
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
The types we would usually look at first for a home in Crawley are single-storey rear extensions, orangery extensions and wraparound extensions, depending on the garden and how the house is laid out.
Areas we cover around Crawley
Site visits are available across Crawley (RH10, RH11). Neighbouring towns we cover include Horsham (7 miles), East Grinstead (8 miles), Haywards Heath (9 miles), Burgess Hill (11 miles), Shoreham-by-Sea (20 miles). For homes towards Surrey, Horley is around 4 miles away.
Popular extension prices in Crawley
We publish guide prices so you can budget before anyone visits. For Crawley they are adjusted by ×1.12, the factor we use across South East England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
Approvals for an extension in Crawley
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Choose an extension type
- Bungalow extensions · from £29,000
- Extensions over a garage · from £26,500
- Orangery extensions · from £33,500
- Single-storey rear extensions · from £23,500
- Kitchen extensions · from £30,000
- Pitched roof extensions · from £24,500
- Extension plans and drawings · from £1,300
- Glass box extensions · from £33,500
- Building regulations for extensions · from £1,000
- Flat roof extensions · from £23,500
- Double-storey extensions · from £42,500
- Side return extensions · from £20,000
- Wraparound extensions · from £40,000
- Conservatory replacement extensions · from £22,000
- Side extensions · from £24,500
- Utility and boot room extensions · from £15,500
- Planning permission for extensions · from £350
- Bedroom extensions · from £29,000
- Timber frame extensions · from £23,500
- Annexe extensions · from £61,500
- Porch extensions · from £4,450
- Home office extensions · from £17,500
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Crawley
How much does an extension cost in Crawley?
Using our South East England factor (×1.12), a standard-spec single-storey extension of 20 m² is a guide £45,500 to £58,500 including VAT, and a 32 m² two-storey extension £64,500 to £84,500. Your written price follows the survey.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
How long does an extension take in Crawley?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Book a free site visit in Crawley
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.