- Guide price
- £4,050–£7,450
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Powys at a glance
- Largest towns
- Newtown, Brecon
- Postcode areas
- LD, SY
- Building control
- Powys County Council
- Neighbouring areas
- Blaenau Gwent · Ceredigion · Merthyr Tydfil · Torfaen
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a green roof cost in Powys?
Guide prices including VAT at Wales rates. 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 | £4,050–£7,450 |
| Extension (20 m²), EPDM, new deck + insulation | £2,600–£4,500 |
Which flat roofs are common in Powys?
Flat roofs in Powys sit on low-rise post-war blocks of flats, shops with flat-roofed rear stores below flats and 1960s and 1970s link-detached houses with flat-roofed garages and porches. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in Wales
Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. Renovated roofs are upgraded to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K under the Welsh Approved Document L. In Powys the application goes to Powys County Council. More on the rules.
Can my flat roof take the weight of a green roof?
Not every roof can, which is why we check the structure before quoting. A sedum roof is light compared with an intensive garden, but its growing medium holds water, and a saturated build-up adds significant weight to the roof.
We look at the joist sizes, spans and spacing, the condition of the deck and what the roof sits on. On a recently built extension with generously sized joists, an extensive green roof may be straightforward. On an older garage or a roof with undersized or rotten timbers, the structure may need strengthening, or a structural engineer's calculation may be needed before we can go ahead.
In England, a new roof covering that adds 15% or more to the weight of the roof triggers building control approval, and a green roof will often fall into that category. We handle building control where it is needed. The building regulations page covers the approval routes in each nation.
Can a green roof go on my existing flat roof?
Only if the existing waterproofing is sound, root-resistant or protected by a root barrier, and has plenty of life left. In most cases it makes more sense to lay a green roof as part of a replacement.
Once the sedum, substrate and drainage layers are down, the membrane underneath is hard to inspect and expensive to repair, because the green layers have to be lifted to get to it. Putting a green roof on an ageing covering risks paying for the greenery twice. Our repair or replace guide helps you judge whether your current roof is a sensible base.
As for planning, re-covering a house roof normally needs no application if its appearance doesn't change materially. Because a green roof does change how a roof looks, check with your council, especially for listed buildings, conservation areas and roofs that are easily seen. The planning guide has more.
Which towns in Powys do we cover?
Green and sedum roofs in Powys: questions
Which towns in Powys do you cover?
All of Powys. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a green roof cost in Powys?
£4,050–£7,450 for a 20 m² insulated extension roof finished as a sedum green roof, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Powys?
All of Powys, including the LD, SY postcode areas. Send your full postcode and we'll confirm.
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.
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.
Do I need to water a sedum roof?
Usually only in the first season, during long dry spells, while the blankets establish. After that, sedum copes with dry weather well.
Everything about green and sedum roofs → · All flat roofing in Powys →