A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
West Sussex is part of our UK-wide coverage for a new flat roof. Places we cover include Crawley, Worthing, Bognor Regis and Littlehampton, and we travel to smaller communities across the area as well. Since your property is in England, the relevant planning and building rules are the ones set there. In the South East, budget around £2,200–£5,000 with VAT; the figure is confirmed after a survey that costs you nothing.
- Guide price
- £2,200–£5,000 inc VAT
- Time on site
- 1–3 days for most roofs
- Planning rules
- England
- Price level
- About 12% above the national guide
- Towns listed
- 12
- Survey
- Free, with a written quote
Flat roofs prices in West Sussex
Here is how the guide price for a new flat roof breaks down in West Sussex. We start from national figures and adjust for the South East, which comes out about 12% above the national guide. The resulting range, VAT included, is £2,200–£5,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in West Sussex |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £900–£2,200 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £2,200–£5,000 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £4,500–£10,000 |
What moves the price up or down:
- Roof area and access to the roof
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
Scope of the work
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
Homes in West Sussex
Chichester has Georgian brick streets, Downland villages use flint and brick, and Horsham stone slabs cover some older roofs. Worthing and Bognor Regis have interwar and post-war bungalows and semis, Crawley was planned as a post-war new town, and Wealden villages to the north feature tile-hanging and timber framing.
Bungalows commonly suit loft conversions and extensions; new-town homes often take window, roofline and cladding renewal. Flint and stone properties need lime repointing, and coastal homes may need external decorating more often.
Coastal towns face salt-laden south-westerly winds, while Wealden clay inland can shrink and swell with the seasons.
Planning and building rules in West Sussex
As West Sussex is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
Re-roofing a house with similar materials does not usually need planning permission in England. Listed buildings and conservation areas may need consent if the covering changes.
Replacing more than a quarter of a roof’s covering counts as renovation under Building Regulations, so the work is notified and the roof insulation may need upgrading. Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a new flat roof.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Getting ready
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
On site to finish
Our trades complete a new flat roof while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
How we work
Questions about a new flat roof in West Sussex
Why does water sit on my flat roof?
Ponding water on a flat roof is usually caused by inadequate falls, sagging joists, a deck that has dipped or blocked outlets. Small puddles that dry within a day or two are not always a problem, but standing water speeds up wear and finds any weakness. A new roof can be laid on firring strips or tapered insulation to create proper falls. We check falls during the survey.
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
How much will a new flat roof cost in West Sussex?
As a guide, expect to pay £2,200–£5,000 including VAT for a new flat roof in West Sussex. That range is adjusted for the South East, which runs about 12% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
How long does a flat roof last?
A well-installed EPDM or GRP flat roof can last 25 years or more, while torch-on felt systems typically last around 15–25 years, depending on quality and exposure. Lifespan depends on correct falls, good detailing at edges and upstands, and keeping outlets clear. Foot traffic, ponding and poor ventilation shorten it. Annual checks help catch small problems early.
Can you repair my flat roof instead of replacing it?
A flat roof can often be repaired if the damage is limited to a small split, a failed joint or a loose upstand and the rest of the covering is sound. If the deck is soft, the covering is blistered or cracked across the roof, or leaks keep returning, replacement is usually better value. We assess the whole roof and give you an honest recommendation.
Towns in West Sussex
Find your town below. Every place listed in West Sussex is covered for a new flat roof, with the same survey, written quote and fixed-price process.