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.
Every house in Derry/Londonderry is a little different, so we never price a loft conversion from a brochure. We look at the structure, access and existing finishes first, then put in writing a fixed figure for the scope we settle on. As a rough steer, homeowners in Northern Ireland should budget £26,000–£56,000 including VAT, with work typically taking 6–10 weeks on site.
- Guide price
- £26,000–£56,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- BT48
- Planning rules
- Northern Ireland
- Local area
- Derry
- Survey
- Free, with a written quote
What should you budget for a loft conversion in Derry/Londonderry?
What will a loft conversion cost in Derry/Londonderry? Our guide range is £26,000–£56,000 including VAT. That figure is adjusted for Northern Ireland, about 14% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Derry/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 |
Expect these to shape the final quote:
- 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
What do you get?
- Structural calculations and steel beams where needed
- New floor joists strong enough for a habitable room
- Dormer, hip-to-gable or rooflight structure as agreed
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
Homes in 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.
With that background in mind, here is how we typically handle a loft conversion for homes in Derry/Londonderry, from the first visit to the finished result.
Permissions for a loft conversion in Derry/Londonderry
Homes in Derry/Londonderry come under the regulations for Northern Ireland, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
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.
How does the job run?
We look at the job
A free survey comes first. It gives us what we need to price a loft conversion properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Quote in writing
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.
Plan and prepare
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Derry/Londonderry property.
The work itself
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
How we work
Common questions
Which postcodes in Derry/Londonderry do you cover?
We cover BT48, along with the rest of County Londonderry. 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.
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.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Does the Party Wall Act apply to a loft conversion?
The Party Wall etc. Act 1996 applies in England and Wales only, and loft conversions on terraced and semi-detached houses often fall within it, because steel beams are usually set into the shared wall. You must serve notice on the neighbour before work starts, and they can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act. We tell you during the survey whether notices are likely.
Can I put a bathroom in my loft?
A bathroom or shower room can usually be added in a loft conversion if waste pipes can reach the soil stack with enough fall, or a pumped system can be used. Dormers make this easier because they give standing height for a shower. Water pressure, extraction and the position of the boiler also matter. We plan the bathroom layout at the design stage so pipes are hidden in the structure.
Also covering areas around Derry/Londonderry
Our coverage in Derry/Londonderry includes BT48. We also travel to Strabane, Limavady and Coleraine, so neighbouring addresses are looked after on exactly the same terms as those in town.