- Guide price
- £1,350–£2,500
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Cumbria at a glance
- Largest towns
- Carlisle, Barrow-in-Furness, Kendal, Whitehaven
- Postcode areas
- CA, LA
- Building control
- Cumberland Council and Westmorland and Furness Council
- Neighbouring areas
- Lancashire · County Durham · Tyne and Wear · Northumberland
- Guide price region
- North West (−5% on West Midlands rates)
How much does a new dormer roof cost in Cumbria?
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 Cumbria?
Flat roofs in Cumbria sit on bungalows with flat-roofed side extensions and dormers, terraced streets with flat-roofed rear kitchens and bathrooms and low-rise post-war blocks of flats. 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 Cumbria the application goes to Cumberland Council and Westmorland and Furness Council. More on the rules.
How long does a dormer roof replacement take?
The roofing itself typically takes one to three days, with scaffold going up before and coming down after. Allow a few extra days overall for the scaffold.
The room under the dormer stays usable, though it will be noisy during the strip-out, and dust can fall through gaps around the ceiling. Moving furniture away from the window helps. Scaffold usually needs space on the drive or garden, and sometimes a pavement licence. GRP has a strong smell while it cures, so keep the dormer windows shut on the day it is laid.
Why is scaffold and tile detailing so important on a dormer?
Because a dormer roof is high, small and surrounded by a pitched tiled roof, most failures happen at the edges rather than in the middle. Safe access is what allows those edges to be done properly.
Ladders alone do not give a safe working platform at that height, and every roof is treated as fragile until a competent person confirms otherwise. Scaffold with edge protection lets the team work along the front and sides of the dormer, and reach the junction with the main roof.
The back of the dormer is where most leaks start. The new membrane has to turn up under the tiles or slates, with a flashing that sheds water over it. Where the old detail used lead, we reinstate or replace it. Small roofs also leave little room for error at the drip edge: the front trim must throw water clear of the window frame and fascia, and any gutter has to be big enough for the area it drains. Dormer cheeks with tile hanging or cladding are checked for gaps that let water behind.
If you are also planning insulation upgrades or work on the main roof, tell us at survey so the scaffold can be shared.
Which towns in Cumbria do we cover?
Dormer roofs in Cumbria: questions
Which towns in Cumbria do you cover?
All of Cumbria. 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 Cumbria?
£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 council handles building control for a flat roof in Cumbria?
It depends on where the roof is: in Cumbria that's Cumberland Council and Westmorland and Furness Council. 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 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.
How long does a GRP dormer roof last?
As an indicative range, GRP lasts 20–40 years with good specification and maintenance.
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