Dormer roofs across East Sussex

Guide price

£1,550–£2,900

Survey

Free for new and replacement roofs

Quote

Fixed, in writing

Coverage

England, Wales, Scotland, NI

How much does a new dormer roof cost in East Sussex?

Guide prices including VAT at South East rates. The fixed price comes after a free survey for new and replacement roofs.

Which flat roofs are common in East Sussex?

Flat roofs in East Sussex sit on shops with flat-roofed rear stores below flats, terraced streets with flat-roofed rear kitchens and bathrooms and 1960s and 1970s link-detached houses with flat-roofed garages and porches. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain. 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 East Sussex the application goes to Brighton & Hove City Council, Eastbourne Borough Council, Hastings Borough Council and 3 other councils. More on the rules.

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.

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.

Which towns in East Sussex do we cover?

• Brighton
• Eastbourne
• Hastings
• Bexhill-on-Sea
• Hailsham
• Seaford
• Rottingdean
• Crowborough
• Portslade
• Peacehaven
• Uckfield
• Lewes

Everything about dormer roofs → · All flat roofing in East Sussex →