- Guide price
- £14,550–£23,950
- 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 commercial flat roof 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 |
|---|---|
| Commercial roof (100 m²), single-ply + insulation | £14,550–£23,950 |
| Condition survey and leak investigation | £170–£330 |
| Block of flats (150 m²), felt + insulation + scaffold | £17,100–£29,900 |
Which flat roofs are common in West Sussex?
Flat roofs in West Sussex sit on 1930s semis with flat-roofed garages and kitchen extensions, 1960s and 1970s link-detached houses with flat-roofed garages and porches and lock-up garage blocks on estates. 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 you offer condition surveys and phased budgets?
Yes. A condition survey with a written report is a paid service, guide £170–£330 for a typical single roof, with larger or multi-roof sites priced before we attend. A survey and quote for replacement work is free.
The report covers the covering, upstands, outlets, edges and rooflights, signs of ponding or wet insulation, and what needs doing now, soon and later. You can then plan a phased programme: urgent repairs first, then re-roofing in sections over one or more budget years, with each phase priced separately in your written quote.
Re-covering more than half of a roof over heated space usually triggers the thermal element rules, so the insulation is upgraded towards the renovation U-value where feasible; in England the non-domestic target is 0.18 W/m²K. We handle building control where it is needed. See building regulations and flat roof surveys.
Can you work around our trading hours and site rules?
Yes. Most commercial roofs can be replaced while the building stays open, and we agree the programme with you before any work starts.
That normally means set working hours, delivery and skip positions that keep entrances and fire exits clear, and phasing the roof so each section is watertight before the team leaves site. Noisy tasks such as strip-out can be timed for quieter periods, and early starts or weekend working can be arranged where your site allows. We tell you in advance which areas below the roof may be affected, so stock and equipment can be protected or moved.
Where torch-on felt is specified, the team works under your hot works permit system, with a fire watch after the torch is put away. If your site does not allow naked flames, we specify a cold-applied, self-adhesive or other flame-free system instead. Tenants, alarm companies and mechanical contractors are coordinated through one named contact.
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
Commercial flat roofing 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 commercial flat roof cost in West Sussex?
£14,550–£23,950 for a 100 m² commercial roof in single-ply with 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 West Sussex?
It depends on where the roof is: in West Sussex that's Crawley Borough Council, Worthing Borough Council, Arun District Council and 4 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.
Can the cost be spread over more than one budget year?
Yes. We can price a phased programme with each section shown separately, starting with the most urgent areas, so you can plan the spend while the building stays protected.
What happens to air conditioning units and other roof plant?
Plant can often stay in place, with the new roof detailed around its supports. Where it has to be isolated and lifted, your mechanical contractor does that while we re-roof beneath it, and we agree the timing at survey stage.
Can our existing roof be overlaid instead of stripped?
Often, if the survey shows the existing covering is sound, dry and firmly bonded. Wet insulation, a soft deck or several old layers mean a strip-out is the better long-term answer.
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