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.
Across County Londonderry, people look into a loft conversion to replace something worn out, to make the house work better for them, or to get it ready for a sale. We cover Derry/Londonderry, Coleraine, Limavady and Magherafelt and the smaller towns around them, working to the rules that apply in Northern Ireland. Expect a guide of £26,000–£56,000, VAT included, in Northern Ireland, and every quote follows a free visit.
- Guide price
- £26,000–£56,000 inc VAT
- Time on site
- 6–10 weeks on site
- Planning rules
- Northern Ireland
- Price level
- About 14% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
Loft conversions prices in County Londonderry
Prices for a loft conversion vary from house to house, but in County Londonderry most projects fall within £26,000–£56,000 including VAT. That reflects costs in Northern Ireland, about 14% below the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in County Londonderry |
|---|---|---|
| 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 |
Your price depends mostly on:
- 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
- Staircase layout, fire doors and the level of finishes
Scope of the work
- New floor joists strong enough for a habitable room
- 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
- Electrics, heating and plumbing by qualified trades, with certificates
Housing across County Londonderry
Derry has Georgian and Victorian terraces around its walled city, alongside large post-war estates and newer developments. Coleraine, Limavady and Magherafelt mix older town centres with semis and estates, Portstewart has seaside villas, and rural areas have many detached homes and bungalows, often roughcast.
Terraces suit loft conversions and rear extensions, while rural bungalows commonly take extensions, loft rooms and driveways. Roughcast homes often need re-rendering, and coastal houses need roofline and window renewal.
The north coast faces Atlantic wind, rain and salt, and the Sperrins inland are colder and wetter.
Planning and building rules in County Londonderry
As County Londonderry is in Northern Ireland, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
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
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a loft conversion.
Written quote
After the survey we send a quote for a loft conversion that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Booking the work
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Build and hand over
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.
How we work
Frequently asked questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a loft conversion, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
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.
What fire safety measures does a loft conversion need?
A loft conversion needs a safe way out in a fire, because the new room is high above the ground. This usually means a protected stair route down to an exit, with fire doors onto the stairway, mains-linked smoke alarms on each floor and sometimes an escape window. The exact approach depends on your house layout. Building control checks these measures before signing off the work.
Where will the new staircase go?
The new staircase usually sits above the existing stairs, rising from the landing so it uses space that is already circulation. Sometimes it needs to come from a small bedroom or box room, which reduces that room's size. Building regulations set rules on headroom, step size and handrails, with some flexibility for lofts. We look at options at the survey and show you how each affects the floor below.
Do you cover Derry/Londonderry, Coleraine and Limavady?
Yes. As well as County Londonderry, we cover Derry/Londonderry, Coleraine and Limavady and the rest of County Londonderry. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Towns in County Londonderry
Find your town below. Every place listed in County Londonderry is covered for a loft conversion, with the same survey, written quote and fixed-price process.