Flat roof replacement in the UK
Full flat roof replacement — new covering, new falls, new upstands, new deck where needed.
Typical UK cost range
£80–£180/m²
National baseline. City-specific ranges are adjusted for local labour and access costs on the city pages below. See the full UK cost guide for the methodology and the factors that move a quote.
What the job involves
Flat roof replacement is priced per square metre of covering, with the system choice (EPDM, GRP, felt, TPO) driving most of the variance. A typical small extension is 15–25 m², which puts full replacement in the £1,200–£4,500 range before scaffold and skip.
A proper replacement includes checking and usually replacing the deck underneath, creating sufficient falls to avoid ponding, and dressing upstands properly into the abutting wall or parapet. Cheap quotes often skip these details.
What changes the price
- System choice — felt cheapest, EPDM mid, GRP or single-ply most expensive.
- Area in m² plus complexity (penetrations, upstands, rooflights).
- Whether the deck underneath is sound or needs replacing.
- Scaffold access and waste removal.
Timeline: Usually 2–5 days on site depending on size.
Pick a city for local pricing
Each city page has adjusted cost ranges, local context, and the roofers in our directory that cover it.
Major English cities
Other English cities
Northern Ireland
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Start my quote requestCommon questions
Which flat roof system lasts longest?
TPO and PVC single-ply for commercial-grade installation, 30+ years. EPDM rubber is the best domestic choice, 25–40 years. GRP is 25–35 years. Felt is 10–15 years — cheap up front but replaced most often.
Do I need planning permission for a flat roof replacement?
Like-for-like replacement is usually permitted development and doesn’t need planning permission. It does need to comply with Building Regulations Part L (see the Part L guide). Listed buildings and conservation areas are exceptions.
Related guides
Independent rankings — no pay-to-rank. See Methodology, Complaints & corrections.