- Guide price
- £2,650–£4,650
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Greater Manchester at a glance
- Largest towns
- Manchester, Oldham, Wigan, Bolton
- Postcode areas
- BL, M, OL, SK, WA, WN
- Building control
- Manchester City Council, Oldham Council, Wigan Council and 7 other councils
- Neighbouring areas
- Cheshire · Lancashire · Merseyside · West Yorkshire
- Guide price region
- North West (−5% on West Midlands rates)
How much does a warm roof upgrade cost in Greater Manchester?
Guide prices including VAT at North West rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,650–£4,650 |
| Extension (20 m²), EPDM with sedum green roof | £4,200–£7,700 |
Which flat roofs are common in Greater Manchester?
Flat roofs in Greater Manchester sit on bungalows with flat-roofed side extensions and dormers, shops with flat-roofed rear stores below flats and 1930s semis with flat-roofed garages and kitchen extensions. The North West is one of England's wetter regions, averaging roughly 1,290 mm of rain a year, so falls, outlets and well-detailed upstands matter more than the membrane colour. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in England
Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In Greater Manchester the application goes to Manchester City Council, Oldham Council, Wigan Council and 7 other councils. More on the rules.
How long does a warm roof last?
The insulation in a warm roof should last for the life of the waterproofing above it, as long as it stays dry. Rigid PIR boards don't settle or slump in the way some loose insulation can.
The waterproofing is what sets the timescale. EPDM is typically quoted at 25 to 50 years, GRP at 20 to 40 years and modern torch-on felt at 15 to 25 years with good specification and care. A warm build-up also helps the deck, because keeping it warm and dry lowers the risk of condensation rot. If the waterproofing fails and water gets into the insulation, the wet boards should be replaced, so leaks need prompt attention. The lifespan guide compares the systems.
Will insulating the roof raise its height, and what about doors and upstands?
Yes. A warm roof makes the roof thicker, often by more than 100 mm depending on the insulation and the U-value target. That extra height is the main thing we plan around.
Waterproofing at a wall usually needs to rise about 150 mm above the finished roof surface, so if the roof gets higher, the upstand has to go higher too. That can be a problem where the roof meets a door threshold, a low window sill, a cavity tray or a rooflight kerb. At the edges, trims and fascias are reset to the new level, and gutters may need to move.
Where there isn't enough height, the options include using thinner, higher-performance insulation, lowering the deck where the structure allows, raising the sill or threshold, or, where it is genuinely not feasible to reach the full target, insulating as far as is reasonable and recording why with building control. We work this out at the survey so there are no surprises on the day.
Which towns in Greater Manchester do we cover?
- Manchester
- Oldham
- Wigan
- Bolton
- Stockport
- Salford
- Rochdale
- Sale
- Bury
- Altrincham
- Middleton
- Ashton-under-Lyne
- Leigh
- Stretford
- Urmston
- Eccles
- Tyldesley
- Hyde
- Walkden
- Prestwich
- Radcliffe
- Cheadle Hulme
- Heywood
- Denton
- Stalybridge
- Ashton in Makerfield
- Westhoughton
- Farnworth
- Saddleworth
- Hindley
- Golborne
- Droylsden
- Royton
- Failsworth
- Hazel Grove
- Irlam
- Horwich
- Bramhall
- Ramsbottom
- Bredbury
- Longsight
Warm roof insulation upgrades in Greater Manchester: questions
Which towns in Greater Manchester do you cover?
All of Greater Manchester. 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 warm roof upgrade cost in Greater Manchester?
£2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, at North West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in Greater Manchester?
It depends on where the roof is: in Greater Manchester that's Manchester City Council, Oldham Council, Wigan Council and 7 other councils. Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. We confirm which applies at the survey.
Does a warm roof stop condensation?
It greatly reduces the risk by keeping the deck warm and placing a vapour control layer on the warm side. Good ventilation in kitchens and bathrooms below still helps.
Can you insulate a flat roof from inside instead?
It is possible, but insulating between or under the joists creates a cold roof, which needs ventilation and carries a higher condensation risk. When the roof is being re-covered anyway, a warm roof from above is usually the better option.
Is there VAT relief on flat roof insulation?
Don't count on it. Insulation fitted as part of a roof replacement is usually treated as part of a single standard-rated job. Check your own case with HMRC guidance or an adviser.
Everything about warm roof insulation upgrades → · All flat roofing in Greater Manchester →