Worthing at a glance
- Postcode districts
- BN11, BN12, BN13, BN14
- Population
- about 113,866 (GeoNames)
- Council area
- Worthing Borough Council
- Building approval
- Worthing Borough Council building control, or a registered building control approver
- Nearest main town
- Brighton, about 10 miles
- Guide price region
- South East (+10% on West Midlands rates)
Why upgrade to a warm roof in Worthing?
Kitchen extensions in Worthing, as elsewhere, produce a lot of moisture from cooking. Under a cold flat roof, that moisture can condense on the deck. A warm roof keeps the deck warm and puts a vapour control layer in the way, which lowers the risk considerably.
In a large town like Worthing, flat roofs are commonly found on newer estates where the first extension roofs are now being replaced or 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.
How much does a warm roof upgrade cost in Worthing?
At South East guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £3,100–£5,350 including VAT. 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), EPDM with sedum green roof | £4,850–£8,900 |
Can a cold flat roof be converted to a warm roof?
Yes, and it is the usual approach when an older cold roof is re-covered. The old covering is stripped, the deck is checked and replaced where needed, and the vapour control layer, insulation and new waterproofing go on top.
The existing insulation between the joists is assessed at the same time. Leaving it in place can create a cold, unventilated gap that traps moisture, so it is often removed or the build-up is designed so that most of the insulation sits above the deck. We decide this case by case once we can see inside the roof. If the covering is still sound and you are only patching it, the upgrade isn't usually required, and our repair or replace guide explains how to decide between the two.
What's included?
- Rigid insulation boards sized to the U-value target
- Survey of the deck, joists and existing insulation
- Vapour control layer on the warm side of the insulation
- Building control or building standards handled where needed
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
- Lancing · 2 mi
- Shoreham-by-Sea · 5 mi
- Portslade · 7 mi
- Littlehampton · 7 mi
- Brighton · 10 mi
- Bognor Regis · 14 mi
Warm roof insulation upgrades in Worthing: questions
Do you cover Worthing?
Yes. Worthing is part of our West Sussex coverage, including postcode districts BN11, BN12, BN13, BN14. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Worthing?
Where the work needs approval it goes to Worthing Borough Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a warm roof upgrade cost in Worthing?
£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.
Can you add insulation over my existing roof without stripping it?
Sometimes, if the existing covering and deck are dry and sound. We will check at the survey and explain the risks, and our overlay or strip guide covers this choice.
How thick does flat roof insulation need to be?
It depends on the insulation product and the U-value target. With common PIR boards, meeting a renovation target usually means well over 100 mm. Thinner, higher-performance boards are available where height is tight.