- Guide price
- £3,100–£5,350
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
East Sussex at a glance
- Largest towns
- Brighton, Eastbourne, Hastings, Bexhill-on-Sea
- Postcode areas
- BN, TN
- Building control
- Brighton & Hove City Council, Eastbourne Borough Council, Hastings Borough Council and 3 other councils
- Neighbouring areas
- West Sussex · Surrey · Kent · London
- Guide price region
- South East (+10% on West Midlands rates)
How much does a new extension 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.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
| Extension (20 m²), GRP, new deck + insulation | £3,300–£5,900 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £3,300–£5,750 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
Which flat roofs are common in East Sussex?
Flat roofs in East Sussex sit on bungalows with flat-roofed side extensions and dormers, 1930s semis with flat-roofed garages and kitchen extensions and low-rise post-war blocks of flats. 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.
Does an extension roof replacement need building regulations?
Usually, yes. An extension roof over a heated room is a thermal element, so replacing most of it typically brings insulation requirements and an approval route.
In England, renovating more than half of the roof means upgrading it towards 0.16 W/m²K where that is technically, functionally and economically feasible. The approval comes from building control or a competent person scheme. A brand-new extension roof is designed to 0.15. Wales usually requires approval for most re-roofing, with a renovation target of 0.16 and a new-extension target of 0.13. Scotland handles this through building standards and the warrant process, and Northern Ireland through district council building control.
Planning is not normally needed to re-cover an extension roof that looks broadly the same afterwards. Turning the roof into a terrace is another matter. We handle building control where the job needs it; see our building regulations page.
How long will my kitchen be disrupted by a new roof?
Most single-storey extension roofs are replaced in two to four working days, depending on size, rooflights and weather. The kitchen usually stays in use throughout.
Expect noise during the strip-out, and occasional dust through gaps around old rooflights, so it helps to cover worktops and move anything fragile off high shelves. We strip only what we can make weathertight by the end of each day. If a rooflight or lantern is being lifted and refitted, there may be a temporary cover over the opening for a short time. Resin systems smell while they cure, so keep the windows below the roof closed on that day.
Which towns in East Sussex do we cover?
- Brighton
- Eastbourne
- Hastings
- Bexhill-on-Sea
- Hailsham
- Seaford
- Rottingdean
- Crowborough
- Portslade
- Peacehaven
- Uckfield
- Lewes
Extension and kitchen roofs in East Sussex: questions
Which towns in East Sussex do you cover?
All of East Sussex. 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 extension roof cost in East Sussex?
£3,100–£5,350 for a 20 m² extension roof in EPDM with a new deck and insulation, at South East 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 East Sussex?
It depends on where the roof is: in East Sussex that's Brighton & Hove City Council, Eastbourne Borough Council, Hastings Borough Council and 3 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.
Why does my extension ceiling get damp in winter if the roof isn't leaking?
That is often condensation in a cold roof, where warm, moist air reaches the cold underside of the deck. A warm-roof replacement with a vapour control layer usually solves it.
Is EPDM or GRP better for a kitchen extension?
Neither is better in every case. EPDM suits simple rectangular roofs with few details, while GRP is often chosen where there are rooflights, corners or occasional foot traffic.
Do I need my neighbour's permission to replace an extension roof?
Not for a like-for-like re-cover in most cases. The Party Wall Act in England and Wales can apply if the work raises or cuts into a shared wall, so we flag that at survey.
Everything about extension and kitchen roofs → · All flat roofing in East Sussex →