Crawley at a glance
- Postcode districts
- RH10, RH11
- Population
- about 124,008 (GeoNames)
- Council area
- Crawley Borough Council
- Building approval
- Crawley Borough Council building control, or a registered building control approver
- Nearest main town
- Brighton, about 20 miles
- Guide price region
- South East (+10% on West Midlands rates)
What does a balcony or terrace in Crawley need?
Door thresholds are a common reason for balcony work in Crawley. Where a door was fitted with a low step-out and no drainage channel, water driven against the frame finds its way under the sill. Re-waterproofing gives the chance to rebuild that detail properly.
In a large town like Crawley, flat roofs are commonly found on low-rise post-war blocks of flats or lock-up garage blocks on estates. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.
How much does balcony or terrace waterproofing cost in Crawley?
At South East guide rates, a 12 m² balcony in a liquid-applied system including scaffold comes to £2,100–£3,600 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Balcony (12 m²), liquid-applied, scaffold | £2,100–£3,600 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
| Extension (20 m²), GRP, new deck + insulation | £3,300–£5,900 |
Do I need planning permission for a balcony or roof terrace?
For a new balcony or roof terrace, generally yes. In England, balconies and raised platforms are not permitted development for houses, so a planning application is normally needed, and the other nations have their own rules.
Re-waterproofing an existing, approved balcony that looks the same afterwards does not normally need planning. Building regulations are a separate question. A terrace over a heated room is a thermal element, so replacing most of it can bring insulation requirements and approval. Turning a flat roof into a terrace also raises structural questions, because people, furniture and paving add load, and it needs guarding, such as a balustrade, that meets the regulations. A structural engineer should confirm that the roof can carry the new use.
Listed buildings and conservation areas add another layer of control. Our building regulations page covers approvals, and our planning permission guide covers the planning side.
What's included?
- Lifting and setting aside of existing paving or decking
- New liquid, GRP, single-ply or asphalt waterproofing
- Strip-out of the failed membrane and deck repairs
- Written workmanship guarantee, with approvals handled where needed
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
Balconies and roof terraces in Crawley: questions
Do you cover Crawley?
Yes. Crawley is part of our West Sussex coverage, including postcode districts RH10, RH11. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Crawley?
Where the work needs approval it goes to Crawley Borough Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does balcony or terrace waterproofing cost in Crawley?
£2,100–£3,600 for a 12 m² balcony in a liquid-applied system including scaffold, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Why is water coming through the ceiling below my balcony?
The usual causes are a failed door threshold, a blocked or poorly sealed outlet, or a fixing through the membrane. A survey, sometimes lifting paving, finds the source.
Is a roof terrace heavier than a normal flat roof?
Yes. Paving, people, planters and furniture all add load, so a structural engineer should confirm the roof can carry it before a terrace is formed.