What is a rooflight loft conversion?
A rooflight loft conversion (sometimes called a roof window conversion) keeps the existing roof shape and adds roof windows that sit flush with the slope. The floor is strengthened, a staircase is added and the space is insulated and finished.
How much does a rooflight loft conversion cost in Coleraine?
In Coleraine, a rooflight loft conversion typically costs £26,000–£38,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Building costs in Northern Ireland run about 14% below the UK average, and the figures for Coleraine are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rooflight conversion | £26,000–£38,500 |
| Higher specification | £38,500–£48,000 |
The biggest cost drivers are:
- Fire safety upgrades
- Staircase position
- Storage and finishes
- Number of roof windows
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a rooflight loft conversion in Coleraine?
The approval route for Coleraine is set by planning law in Northern Ireland. In Northern Ireland roof windows that project no more than 15 centimetres from a road-facing roof slope are permitted development outside conservation areas; listed buildings need consent.
In Northern Ireland building control approval comes from the council, usually through a full plans application or a building notice, with inspections during the work and a completion certificate at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
Handled as part of most rooflight loft conversions:
- Roof windows installed
- Insulation between and under rafters
- Electrics, heating and plastering
- Head-height survey
- Floor joists and any steel beams
- Building control sign-off
How long does it take?
Allow 4 to 6 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Coleraine
Across Northern Ireland, bungalows and chalet bungalows are common, so loft conversions and rear extensions are popular projects.
Coleraine sits in County Londonderry, about 27 miles east of Derry. We cover the whole of Coleraine, including postcodes BT51 and BT52.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about rooflight loft conversions in Coleraine
Do I need planning permission for a rooflight loft conversion in Coleraine?
In Northern Ireland roof windows that project no more than 15 centimetres from a road-facing roof slope are permitted development outside conservation areas; listed buildings need consent.
How long does it take?
Usually 4 to 6 weeks on site.
Can I have a bathroom?
Yes, where there is enough head height at the shower or bath position.
How much does a rooflight loft conversion cost in Coleraine?
In Coleraine, a rooflight loft conversion typically costs £26,000–£38,500 for a typical rooflight conversion, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Do you build rooflight loft conversions in Coleraine?
Yes. We build rooflight loft conversions across Coleraine, including postcodes BT51 and BT52. Every project starts with a free home visit.
Is it cheaper than a dormer?
Yes, usually, because the roof shape stays the same. But you gain less full-height floor space.