- Guide price
- £1,350–£2,500
- 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 new dormer roof 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 |
|---|---|
| Dormer (8 m²), GRP, scaffold | £1,350–£2,500 |
| Single garage (18 m²), EPDM rubber | £1,500–£2,650 |
| Extension (20 m²), GRP, new deck + insulation | £2,850–£5,100 |
Which flat roofs are common in Greater Manchester?
Flat roofs in Greater Manchester sit on 1930s semis with flat-roofed garages and kitchen extensions, newer estates where the first extension roofs are now being replaced and lock-up garage blocks on estates. 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.
Do I need building regulations approval for a dormer roof?
Usually, yes, if you are replacing most of the roof. A dormer roof sits over a heated room, so it counts as a thermal element, and renovating more than half of it normally means upgrading the insulation where feasible.
In England the renovation target is 0.16 W/m²K for homes, approved through building control or a competent person scheme. Wales usually needs approval for most re-roofing work. Scotland works through the council's building standards and, where required, a building warrant. Northern Ireland asks you to contact district council building control before starting.
Insulating above the deck raises the roof slightly. On a dormer, that extra height has to fit under the main roof tiles at the back edge, so the build-up is planned at survey. Re-covering a dormer that looks the same afterwards does not usually need planning permission, but a listed building or conservation area may bring extra controls. More on our building regulations page.
Is GRP or EPDM better on a dormer roof?
GRP fibreglass is often the first choice on a dormer, because it is laid as a liquid resin over a mat and forms neat, rigid edges, corners and drip details on a small roof. It cures to a hard surface that copes with occasional foot traffic during window cleaning or maintenance.
EPDM rubber works well on a plain rectangular dormer and can usually be laid as one sheet, with no field joins. Unlike GRP, it does not depend on resin curing conditions on the day. Torch-on felt can be used, but working a torch close to timber cladding, fascias and tiles needs extra care, so a cold-applied system is often chosen instead.
We recommend the system after surveying the dormer, its edges and how it meets the main roof.
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
Dormer roofs 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 new dormer roof cost in Greater Manchester?
£1,350–£2,500 for an 8 m² GRP dormer roof including scaffold, at North West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Greater Manchester?
All of Greater Manchester, including the BL, M, OL, SK, WA, WN postcode areas. Send your full postcode and we'll confirm.
Why does my dormer leak at the back where it meets the roof?
That junction is the most common leak point, usually because the upstand or flashing under the tiles has failed. A proper re-roof rebuilds it.
Does the room below need emptying?
No, but moving furniture away from the window and covering the floor is sensible. The room stays usable throughout.
Can you replace the lead on my dormer at the same time?
Yes, where lead forms part of the dormer abutment or cheek flashings, we include renewing it in the roof job.
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