A loft conversion turns unused roof space into a habitable room such as a bedroom, bathroom or office, with a proper staircase, insulation, fire protection and natural light from rooflights or a dormer.
Getting a loft conversion right in Belfast starts with understanding the house you already have: its age, how it was built and what has been altered over the years. We survey first, then commit on paper to a price that holds as long as the scope stays the same. Across Northern Ireland, guide prices run at £26,000–£56,000 including VAT, and homes in Castlereagh, Newtownabbey and Lisburn are covered too.
- Guide price
- £26,000–£56,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- BT1, BT2, BT6, BT7 and BT12
- Planning rules
- Northern Ireland
- Local area
- County Antrim
- Survey
- Free, with a written quote
Loft conversions prices in Belfast
To help you plan, we show what a loft conversion typically costs in Belfast instead of holding figures back for a sales call. The range is £26,000–£56,000 with VAT, using rates in Northern Ireland that are about 14% below the national guide. A free survey then fixes your actual price.
| Type of job | What it usually involves | Guide in Belfast |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £17,000–£30,000 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £27,500–£52,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £43,000–£73,000 |
The main things that change the figure:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Steelwork and any strengthening of walls below
- Adding a shower room or en-suite in the roof
What’s included?
- Structural calculations and steel beams where needed
- Dormer, hip-to-gable or rooflight structure as agreed
- Staircase designed to fit your landing and meet regulations
- Insulation to walls, roof slope and floor
- Fire doors, mains-linked smoke alarms and a protected escape route
- Plastering, internal doors and building control sign-off
Homes in County Antrim
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 loft conversion will involve, though we always confirm the details on site.
Do you need permission in Belfast?
Each UK nation sets its own consent rules, and Belfast is in Northern Ireland. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
In Northern Ireland, loft conversions can be permitted development, with dormers controlled mainly by their position and set-backs rather than a volume limit; front-facing dormers and work in conservation areas usually need planning permission.
Building control approval under the Building Regulations (Northern Ireland) is needed. There is no Party Wall Act in Northern Ireland.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
A visit to your home
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Quote in writing
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
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
Build and hand over
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
Why homeowners choose us
Questions about a loft conversion in Belfast
How long will a loft conversion take?
On a typical home, allow 6–10 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
How much will a loft conversion cost in Belfast?
As a guide, expect to pay £26,000–£56,000 including VAT for a loft conversion in Belfast. That range is adjusted for Northern Ireland, which runs about 14% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Is my loft suitable for conversion?
A loft is usually suitable for conversion if there is enough head height, a roof structure that can be adapted and space for a staircase. A common rule of thumb is at least 2.2m from the top of the ceiling joists to the underside of the ridge, though dormers and mansards can create height where it is short. Modern trussed roofs need more structural work. We check all of this at the survey.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £26,000–£56,000. A simple rooflight conversion costs less, while hip-to-gable and mansard conversions cost more because they change the roof structure. As a rough guide, allow around £800–£1,700 per square metre of new floor plus fixed costs for the staircase, steels and fees. Adding a shower room is the most common extra. We confirm a fixed price after surveying your loft.
Can we stay at home during a loft conversion?
Most people stay at home during a loft conversion, because much of the work happens from scaffolding outside and the roof is opened up from above. The most disruptive point is near the end, when we break through the ceiling to fit the new staircase, which usually takes a few days. We put up dust screens on the landing and plan noisy work for reasonable hours.
Nearby towns
Homes across BT1, BT2, BT6 and BT7 in Belfast are within our coverage, as are those in Castlereagh, Newtownabbey and Lisburn. If you are just outside these areas, ask anyway, because we work right across the UK.