Dundonald at a glance
- Postcode districts
- BT16
- Population
- about 13,985 (GeoNames)
- Council area
- Lisburn and Castlereagh City Council
- Building approval
- Lisburn and Castlereagh City Council building control
- Nearest main town
- Belfast, about 5 miles
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
What makes a good extension roof in Dundonald?
Rooflights fitted after the roof was built are a frequent source of trouble in Dundonald extensions. If the kerb was not formed properly or the membrane was simply sealed around the frame, leaks follow. Replacing the roof is the chance to rebuild every upstand to a proper standard.
In a town like Dundonald, flat roofs are commonly found on 1930s semis with flat-roofed garages and kitchen extensions or shops with flat-roofed rear stores below flats. 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.
How much does a new extension roof cost in Dundonald?
For Dundonald we use Northern Ireland rates: £2,450–£4,300 is the guide for a 20 m² extension roof in EPDM with a new deck and insulation, VAT included. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,450–£4,300 |
| Extension (20 m²), GRP, new deck + insulation | £2,650–£4,750 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £2,650–£4,600 |
| Single garage (18 m²), EPDM rubber | £1,400–£2,450 |
How long will my kitchen be disrupted by a new roof?
Most single-storey extension roofs are replaced in two to four working days, depending on size, rooflights and weather. The kitchen usually stays in use throughout.
Expect noise during the strip-out, and occasional dust through gaps around old rooflights, so it helps to cover worktops and move anything fragile off high shelves. We strip only what we can make weathertight by the end of each day. If a rooflight or lantern is being lifted and refitted, there may be a temporary cover over the opening for a short time. Resin systems smell while they cure, so keep the windows below the roof closed on that day.
What's included?
- New abutment upstand and flashing, plus rebuilt rooflight kerbs
- Falls set away from the house wall
- Staged strip-out so the room stays weathertight
- Free survey of the roof, abutment and room below
Building control in Northern Ireland
In Northern Ireland, Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where that's feasible. The district council's building control should be contacted before work starts, and we prepare the details it asks for. More on the rules.
Which nearby areas do we also cover?
Extension and kitchen roofs in Dundonald: questions
Do you cover Dundonald?
Yes. Dundonald is part of our County Down coverage, including postcode districts BT16. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Dundonald?
Where the work needs approval it goes to Lisburn and Castlereagh City Council building control. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a new extension roof cost in Dundonald?
£2,450–£4,300 for a 20 m² extension roof in EPDM with a new deck and insulation, at Northern Ireland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Will a new extension roof sit higher than the old one?
Usually, by the thickness of the added insulation. We check the height against the upstairs window sills, door thresholds and wall flashings at survey so everything still works.
How do I know my extension roof needs replacing rather than repairing?
Repeated leaks, a soft deck, wet insulation or widespread cracking point to replacement. A single defect on a dry, sound roof can usually be repaired.