A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
Belfast sits within our coverage for a new flat roof, as do neighbouring Castlereagh, Newtownabbey and Lisburn. Before giving a price we want to see the property: the condition of what's there now, the access, and anything that might need extra work. The guide range for Northern Ireland is £1,700–£3,900 including VAT, and your written quote will spell out exactly what that covers.
- Guide price
- £1,700–£3,900 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- BT1, BT2, BT6, BT7 and BT12
- Planning rules
- Northern Ireland
- Local area
- County Antrim
- Survey
- Free, with a written quote
How much does a new flat roof cost in Belfast?
These are guide costs, not quotes. For a new flat roof in Belfast the range is £1,700–£3,900, VAT included, reflecting prices in Northern Ireland that are about 14% below the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Belfast |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £700–£1,700 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £1,700–£3,900 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £3,400–£7,700 |
The main things that change the figure:
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
- Number of rooflights, pipes and upstands to detail
Scope of the work
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- Upstands, flashings and drip edges finished neatly
- Rooflights refitted or replaced where required
Local housing and a new flat roof
Belfast has long rows of red-brick Victorian terraces, Edwardian villas in the north and south of the city and large post-war estates, while towns such as Ballymena, Antrim, Larne and Carrickfergus mix terraces, semis and newer developments. Dark basalt appears in older rural buildings, and pebbledash or roughcast is a very common finish.
Terraces suit loft conversions and rear extensions, and many need window and roof renewal. Pebbledashed homes commonly need re-rendering, and detached rural houses often take extensions, porches and driveways.
If your house in Belfast fits one of these patterns, it helps us anticipate what a new flat roof will involve, though we always confirm the details on site.
Permissions for a new flat roof in Belfast
Which rules apply depends on where you live. For Belfast, the answer is Northern Ireland, and the points below reflect that; we verify them with the council before quoting.
In Northern Ireland, re-roofing with similar materials does not usually need planning permission outside listed buildings and conservation areas.
Significant re-roofing should be checked with building control under the Building Regulations (Northern Ireland). Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
Free site survey
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a new flat roof, and photograph or measure anything the quote needs to reflect.
Price and scope agreed
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Getting ready
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
On site to finish
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
What you can expect from us
Common questions
Why does water sit on my flat roof?
Ponding water on a flat roof is usually caused by inadequate falls, sagging joists, a deck that has dipped or blocked outlets. Small puddles that dry within a day or two are not always a problem, but standing water speeds up wear and finds any weakness. A new roof can be laid on firring strips or tapered insulation to create proper falls. We check falls during the survey.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
How much does a new flat roof cost?
Re-covering a typical 15–25m² extension or garage roof costs £1,700–£3,900. As a guide, allow around £75–£170 per square metre plus fixed costs for stripping, waste and access, with torch-on felt at the lower end and GRP or EPDM with new decking or insulation at the top. Small dormer and porch roofs cost less overall but more per square metre. We confirm a fixed price after the survey.
Which postcodes in Belfast do you cover?
We cover BT1, BT2, BT6 and BT7, along with the rest of County Antrim. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Should I insulate my flat roof when it is replaced?
Replacing a flat roof is the most cost-effective time to add insulation, because the covering is already off. A warm roof, with insulation laid above the deck, keeps the structure warm and reduces condensation risk. Building regulations may require insulation when a large part of the roof is renewed. It raises the roof height slightly, which affects trims and upstands.
Near Belfast
Belfast and its BT1, BT2, BT6 and BT7 postcodes are part of our coverage. Homeowners in Castlereagh, Newtownabbey and Lisburn can also book a free survey with us and receive a written price for their job.