Extensions over a garage across Crawley
From the first sketch to final sign-off, we plan and build over-garage extensions in Crawley and the surrounding West Sussex area.
- Guide price in CrawleyFrom £26,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsRH10, RH11
Working in Crawley
We cover Crawley and the postcode districts RH10, RH11. Nearby, we also take on projects in Horsham (7 miles), East Grinstead (8 miles), Haywards Heath (9 miles), Burgess Hill (11 miles).
For homes towards Surrey, Horley is around 4 miles away. The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
Is an over-garage extension right for your house?
- Families needing a bedroom without losing garden
- Detached and link-detached houses with an attached garage
- Homes where the landing can connect to the new room
Do I need planning permission in Crawley?
In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
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).
How much does an over-garage extension cost in Crawley?
For Crawley we adjust our national guide rates by ×1.12, the factor we use for South East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Crawley: £2,020 to £3,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £26,500 – £33,000 | £28,000 – £36,500 | £36,000 – £46,000 |
| Over a large single garage 16 m² | £32,000 – £39,500 | £37,500 – £48,500 | £48,000 – £61,000 |
| Over a double garage 24 m² | £48,000 – £59,500 | £56,000 – £73,000 | £72,500 – £91,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Crawley home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about over-garage extensions
Do I need building regulations approval in Crawley?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Crawley, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for an over-garage extension in Crawley?
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.
How much does a room over a garage cost?
Our guide range is about £2,020 to £3,810 per m² including VAT. A single-garage room of about 12 m² usually costs £28,000 to £36,500 at standard spec, more if the garage needs rebuilding.
Does building over a garage need planning permission?
In England and the rest of the UK, adding a storey over a side garage almost always needs a planning application, because two-storey side extensions are outside permitted development.
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.