- Guide price
- £750–£1,300
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Devon at a glance
How much does a porch or bay roof cost in Devon?
Guide prices including VAT at South West rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Porch or bay (4 m²), EPDM | £750–£1,300 |
| Single garage (18 m²), EPDM rubber | £1,650–£2,900 |
| Extension (20 m²), GRP, new deck + insulation | £3,100–£5,550 |
Which flat roofs are common in Devon?
Flat roofs in Devon sit on newer estates where the first extension roofs are now being replaced, 1960s and 1970s link-detached houses with flat-roofed garages and porches and low-rise post-war blocks of flats. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage. 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 Devon the application goes to Plymouth City Council, Exeter City Council, Torbay Council and 5 other councils. More on the rules.
Why do small porch and bay roofs carry a minimum charge?
Because a small roof needs nearly the same set-up as a larger one: a team, safe access, materials, trims, waste removal and travel. The roof area is only part of the cost.
A 2 m² canopy and a 6 m² bay still both need a full strip, a deck check, edge trims, a wall flashing and the same care at the drip edge. That is why our full re-roofs carry a minimum charge rather than being priced purely per square metre. It is also why bundling makes sense: if you have a porch, a bay and a garage, pricing them together usually works out better than three separate visits.
The junction with the house wall deserves the most attention on a porch. Many leaks blamed on a porch roof are actually water tracking behind a failed flashing or through porous brickwork above. We check the wall, the flashing and the frame head before recommending a new roof. If the problem is only the flashing, a targeted repair may be enough. Our flat roof leaks guide explains how leaks are traced.
Do I need permission to re-roof a porch or bay?
Usually not. Re-covering a porch or bay roof without materially changing how it looks does not normally need planning permission, and an unheated open porch is not usually a thermal element.
The picture changes if the bay or porch is part of a heated room: replacing most of the roof can then bring it under the insulation rules for renovated roofs, which may need building control approval in England, a check in Wales, building standards in Scotland or district council building control in Northern Ireland. On a very small roof, adding insulation may not be technically feasible because of the height available below the window sill above. We assess that at survey.
Listed buildings need consent for changes that affect their character, and conservation areas can restrict changes to the front of a house. See our building regulations page for more detail.
Which towns in Devon do we cover?
Porch, bay and canopy roofs in Devon: questions
Which towns in Devon do you cover?
All of Devon. 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 porch or bay roof cost in Devon?
£750–£1,300 for a small 4 m² porch or bay roof in EPDM, at South West 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 Devon?
It depends on where the roof is: in Devon that's Plymouth City Council, Exeter City Council, Torbay Council and 5 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 a bay window roof be replaced without scaffold?
A ground-floor bay usually can, using a tower or platform. A first-floor bay generally needs a small scaffold for safe access.
How long will a new porch roof last?
With good specification and maintenance, EPDM is indicatively 25–50 years and GRP 20–40.
Why is my porch roof leaking when the felt looks fine?
The water is often coming from the wall junction, not the roof surface. A failed flashing, cracked mortar or porous brick above can let water in behind the upstand.
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