- Guide price
- £650–£1,100
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
County Londonderry at a glance
- Largest towns
- Derry/Londonderry, Coleraine, Limavady, Magherafelt
- Postcode areas
- BT
- Building control
- Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District Council
- Neighbouring areas
- County Tyrone · County Antrim · County Armagh · Belfast
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
How much does a porch or bay roof cost in County Londonderry?
Guide prices including VAT at Northern Ireland 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 | £650–£1,100 |
| Single garage (18 m²), EPDM rubber | £1,400–£2,450 |
| Extension (20 m²), GRP, new deck + insulation | £2,650–£4,750 |
Which flat roofs are common in County Londonderry?
Flat roofs in County Londonderry sit on 1960s and 1970s link-detached houses with flat-roofed garages and porches, low-rise post-war blocks of flats and terraced streets with flat-roofed rear kitchens and bathrooms. Northern Ireland averages roughly 1,150 mm of rain a year, spread over many wet days, so a roof that sheds water quickly to clear outlets lasts far longer than one that holds puddles. Approximate 1991–2020 regional averages based on Met Office data.
Building control in Northern Ireland
In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where feasible. In County Londonderry the application goes to Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District Council. More on the rules.
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.
How long does a porch roof replacement take?
Most porch and bay roofs are replaced in a single day, weather permitting. GRP or liquid systems may need a return visit for a topcoat once the first coat has cured.
Disruption is minimal. You may need to use another door while a front porch is being re-roofed, and the area below should be kept clear for safety. A ground-floor bay can usually be reached from a tower or platform steps, while a first-floor bay may need a small scaffold. The window below stays usable, though it is best kept closed while resin is curing.
Which towns in County Londonderry do we cover?
Porch, bay and canopy roofs in County Londonderry: questions
Which towns in County Londonderry do you cover?
All of County Londonderry. 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 County Londonderry?
£650–£1,100 for a small 4 m² porch or bay roof in EPDM, at Northern Ireland 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 County Londonderry?
It depends on where the roof is: in County Londonderry that's Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District Council. In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. We confirm which applies at the survey.
Can a canopy over a front door be re-covered?
Yes. Small canopies are re-covered in the same way as porches, usually in EPDM or GRP, subject to the minimum charge.
Does a porch roof need a gutter?
Not always. Many small porches drip straight off the front edge, but a gutter helps over a doorway or path.
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.
Everything about porch, bay and canopy roofs → · All flat roofing in County Londonderry →