- Guide price
- £3,300–£5,750
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
West Sussex at a glance
- Largest towns
- Crawley, Worthing, Bognor Regis, Littlehampton
- Postcode areas
- BN, PO, RH
- Building control
- Crawley Borough Council, Worthing Borough Council, Arun District Council and 4 other councils
- Neighbouring areas
- East Sussex · Surrey · Hampshire · London
- Guide price region
- South East (+10% on West Midlands rates)
How much does a rooflight upstand cost in West 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, insulation + 1 rooflight upstand | £3,300–£5,750 |
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
| Extension (20 m²), EPDM with sedum green roof | £4,850–£8,900 |
Which flat roofs are common in West Sussex?
Flat roofs in West Sussex sit on low-rise post-war blocks of flats, lock-up garage blocks on estates and shops with flat-roofed rear stores below 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 West Sussex the application goes to Crawley Borough Council, Worthing Borough Council, Arun District Council and 4 other councils. More on the rules.
Do rooflights in flat roofs need building regulations approval?
Usually, yes, for a new opening, because cutting through the roof and trimming joists is a structural alteration. Approval may also be needed because the roof itself is being re-covered.
New rooflights need to meet the energy efficiency standards for glazing, so that the unit doesn't become a weak point in an insulated roof. Many rooflights have a laminated inner pane, so that if the glass breaks it stays in place rather than falling into the room, which is worth asking for over kitchens, living spaces and stairs. Close to a boundary, the fire performance of the roof, including any rooflights, can matter under the fire safety rules.
Whether you need planning permission depends on the property and the unit. A raised lantern changes the roofline more than a flat rooflight, and listed buildings and conservation areas have stricter rules, which also differ between the four nations. We handle building control or building standards where it is needed. The building regulations page and the planning guide explain more.
How long does a rooflight upstand last?
A properly built, insulated upstand with waterproofing dressed to the maker's details should last as long as the roof covering around it. The rooflight's own seals and opening parts may need attention sooner.
Upstands fail early when they are too low, poorly insulated or built on a deck that moves. Keeping the area around the rooflight clear of leaves and debris, checking the corners after storms from a safe position and cleaning the glazing gently all help. Never lean on or stand on a rooflight: most are fragile, and the roof around them should be treated as fragile too. The maintenance guide covers routine checks.
Which towns in West Sussex do we cover?
- Crawley
- Worthing
- Bognor Regis
- Littlehampton
- Horsham
- Haywards Heath
- Chichester
- Burgess Hill
- East Grinstead
- Shoreham-by-Sea
- Lancing
Rooflights in flat roofs in West Sussex: questions
Which towns in West Sussex do you cover?
All of West 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 rooflight upstand cost in West Sussex?
£3,300–£5,750 for a 20 m² insulated EPDM extension roof with one rooflight upstand, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in West Sussex?
All of West Sussex, including the BN, PO, RH postcode areas. Send your full postcode and we'll confirm.
Do you supply rooflights and lanterns?
We fit rooflights and lanterns as part of a flat roof job, but we don't sell them as a separate product. If you've chosen a unit, we'll build the upstand to suit it.
How high should a flat rooflight upstand be?
Usually at least 150 mm from the finished roof surface to the top of the waterproofing, so the joint stays above standing water. Some rooflight makers specify more.
Why does my rooflight drip in winter?
If it only drips in cold weather and not when it rains, it is probably condensation on a cold, poorly insulated upstand or older glazing. Better ventilation helps, and an insulated kerb and modern unit usually fix it.
Everything about rooflights in flat roofs → · All flat roofing in West Sussex →