Portstewart at a glance
- Postcode districts
- BT55
- Population
- about 8,394 (GeoNames)
- Council area
- Causeway Coast and Glens Borough Council
- Building approval
- Causeway Coast and Glens Borough Council building control
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
What makes a good extension roof in Portstewart?
Condensation drives some replacements in Portstewart. Older extension roofs were often built cold, with insulation between the joists and no reliable vapour control. Warm air from the kitchen reaches the cold deck, moisture builds up and the timber suffers. A warm roof deals with the cause, not just the stain.
In a town like Portstewart, flat roofs are commonly found on bungalows with flat-roofed side extensions and dormers or 1960s and 1970s link-detached houses with flat-roofed garages and porches. 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 Portstewart?
Guide price in Portstewart: £2,450–£4,300 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at Northern Ireland rates. 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?
- Staged strip-out so the room stays weathertight
- Building control handled where needed, and a written workmanship guarantee
- Free survey of the roof, abutment and room below
- Falls set away from the house wall
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 Portstewart: questions
Do you cover Portstewart?
Yes. Portstewart is part of our County Londonderry coverage, including postcode districts BT55. 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 Portstewart?
Where the work needs approval it goes to Causeway Coast and Glens Borough 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 Portstewart?
£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.
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.
Can you keep my existing roof lantern?
Often, if the lantern itself is sound. We lift it, rebuild the kerb, dress the new membrane up the upstand and refit the lantern.