Banstead at a glance
- Postcode districts
- SM7
- Population
- about 46,280 (GeoNames)
- Council area
- Reigate and Banstead Borough Council
- Building approval
- Reigate and Banstead Borough Council building control, or a registered building control approver
- Nearest main town
- Crawley, about 14 miles
- Guide price region
- South East (+10% on West Midlands rates)
Why choose a green roof in Banstead?
Homeowners in Banstead building a new extension may find a green roof can help with a planning application, as some councils encourage them for biodiversity and slower rainwater run-off. It is worth raising early with your designer, before the roof structure is drawn up, so the joists can be sized for the extra weight.
Banstead's flat roofs are mostly on 1930s semis with flat-roofed garages and kitchen extensions, with plenty on 1960s and 1970s link-detached houses with flat-roofed garages and porches too. 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 a green roof cost in Banstead?
At South East guide rates, a 20 m² insulated extension roof finished as a sedum green roof comes to £4,850–£8,900 including VAT. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM with sedum green roof | £4,850–£8,900 |
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
How long does a green roof last and how much maintenance does it need?
A well-built extensive green roof needs one or two maintenance visits a year, and the plant layer can help protect the membrane from sunlight and temperature swings.
Typical maintenance means pulling out weeds and tree seedlings before they root, clearing outlets and the gravel strips around edges, filling in any bare patches, and adding a slow-release feed if the sedum looks thin. Sedum is drought-tolerant once established, but newly laid blankets may need watering in a long dry spell during the first season.
The waterproofing underneath has the same expected life as on any other roof of that system. A green roof also slows down rainwater run-off from the roof and, when sedum flowers, attracts bees and other insects. Some councils encourage green roofs for those reasons, so it is worth mentioning one in a planning application for a new extension. Our maintenance guide covers routine checks.
What's included?
- Pre-grown sedum blankets laid and watered in
- Structural check of joists, deck and supports
- Root-resistant membrane or separate root barrier
- Warm or inverted build-up to suit the roof
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?
Green and sedum roofs in Banstead: questions
Do you cover Banstead?
Yes. Banstead is part of our Surrey coverage, including postcode districts SM7. 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 Banstead?
Where the work needs approval it goes to Reigate and Banstead 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 a green roof cost in Banstead?
£4,850–£8,900 for a 20 m² insulated extension roof finished as a sedum green roof, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Can I walk on a green roof?
Only for maintenance, and only where it is safe. Most extensive green roofs on homes aren't designed as roof terraces, and a terrace generally needs planning permission and edge protection.
Can you put a green roof on a pitched roof?
We install green roofs on flat roofs only. Sloping green roofs need extra restraint to stop the growing medium slipping, and they are a specialist job outside our work.