Grantham at a glance
- Postcode districts
- NG31
- Population
- about 44,580 (GeoNames)
- Council area
- South Kesteven District Council
- Building approval
- South Kesteven District Council building control, or a registered building control approver
- Guide price region
- East Midlands (−2% on West Midlands rates)
Why choose a green roof in Grantham?
Rainwater from flat roofs in Grantham runs off quickly in heavy showers. A green roof holds some of that water back and releases it more slowly, which is one reason some owners and developers choose one. The flowering sedum also draws in bees and other insects.
Grantham's flat roofs are mostly on 1960s and 1970s link-detached houses with flat-roofed garages and porches, with plenty on 1930s semis with flat-roofed garages and kitchen extensions too. The East Midlands is drier than the west of Britain, so most flat roofs here fail through age, UV and poor detailing at upstands rather than sheer rainfall.
How much does a green roof cost in Grantham?
At East Midlands guide rates, a 20 m² insulated extension roof finished as a sedum green roof comes to £4,300–£7,900 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 | £4,300–£7,900 |
| Extension (20 m²), EPDM, new deck + insulation | £2,750–£4,800 |
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
- Root-resistant membrane or separate root barrier
- Warm or inverted build-up to suit the roof
- Gravel strips kept clear around edges and outlets
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?
- Sleaford · 11 mi
- Newark-on-Trent · 13 mi
- Melton Mowbray · 14 mi
- Stamford · 19 mi
- West Bridgford · 20 mi
- Arnold · 21 mi
Green and sedum roofs in Grantham: questions
Do you cover Grantham?
Yes. Grantham is part of our Lincolnshire coverage, including postcode districts NG31. 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 Grantham?
Where the work needs approval it goes to South Kesteven District 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 Grantham?
£4,300–£7,900 for a 20 m² insulated extension roof finished as a sedum green roof, at East Midlands guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
What happens if a green roof needs repairing?
The green layers are lifted around the problem area, the membrane is repaired, and the layers are relaid. Building on a sound, long-life membrane in the first place keeps that to a minimum.
Does a green roof leak more than a normal flat roof?
No, as long as it is built correctly. The waterproofing beneath is what keeps water out, and the green layers protect it from sun and weather. The main risk is building it on a weak or ageing membrane.