Wishaw at a glance
- Postcode districts
- ML2
- Population
- about 30,050 (GeoNames)
- Council area
- North Lanarkshire Council
- Building approval
- North Lanarkshire Council building standards
- Nearest main town
- East Kilbride, about 10 miles
- Guide price region
- Scotland (−5% on West Midlands rates)
Why choose a green roof in Wishaw?
Homeowners in Wishaw 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.
In a town like Wishaw, flat roofs are commonly found on low-rise post-war blocks of flats or shops with flat-roofed rear stores below flats. Scotland averages roughly 1,570 mm of rain a year, with the west far wetter than the east, so drainage, falls and wind uplift are part of every specification we write.
How much does a green roof cost in Wishaw?
At Scotland guide rates, a 20 m² insulated extension roof finished as a sedum green roof comes to £4,200–£7,700 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 | £4,200–£7,700 |
| Extension (20 m²), EPDM, new deck + insulation | £2,650–£4,650 |
How is a green roof built on top of a flat roof?
From the bottom up, a green roof is a deck, a waterproofing system with root protection, then drainage, filter, growing medium and plants. The waterproofing does the job of keeping water out. The green layers sit above it.
- Warm roof build-up: vapour control layer, insulation and waterproof membrane on the deck, then the green layers on top. This is the usual choice on a home extension being re-roofed.
- Inverted build-up: waterproofing on the deck, then insulation boards designed to sit above it, then the green layers. This is common on terraces and some commercial roofs.
- Root barrier: roots will exploit any weakness, so the membrane needs to be root-resistant. Some membranes are tested as root-resistant; others need a separate root barrier laid on top.
- Drainage and edges: a drainage layer carries surplus water to outlets, and a gravel or pebble strip is usually left around edges, outlets, upstands and rooflights to keep them clear and accessible.
Upstands still need to rise around 150 mm above the finished surface, which on a green roof means above the top of the growing medium. We check that at the survey, alongside the external fire performance of the build-up where the roof is close to a boundary.
What's included?
- Structural check of joists, deck and supports
- Root-resistant membrane or separate root barrier
- Warm or inverted build-up to suit the roof
- Drainage layer, filter and lightweight growing medium
Building standards in Scotland
In Scotland the building standards technical handbooks (Section 6 for energy) apply, and the council's building standards service decides whether a building warrant is needed. Like-for-like repairs to a roof covering can be exempt; alterations, structural work and new roofs usually need a warrant before work starts. The domestic roof benchmark is 0.12 W/m²K, applied as far as reasonably practicable on an existing roof. More on the rules.
Which nearby areas do we also cover?
Green and sedum roofs in Wishaw: questions
Do you cover Wishaw?
Yes. Wishaw is part of our North Lanarkshire coverage, including postcode districts ML2. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building standards for a flat roof in Wishaw?
Where the work needs approval it goes to North Lanarkshire Council building standards. 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 Wishaw?
£4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, at Scotland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Can a green roof have a rooflight in it?
Yes. The rooflight sits on a raised upstand with a gravel strip around it, so the planting stays clear of the glazing and the upstand stays visible and dry.
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.