What is a hip-to-gable loft conversion?
A hip-to-gable loft conversion replaces the sloping side (the hip) of a semi-detached or detached roof with a vertical gable wall. This extends the ridge and creates enough space for a staircase and a full-size room, usually combined with a rear dormer.
How much does a hip-to-gable loft conversion cost in Lisburn?
In Lisburn, a hip-to-gable loft conversion typically costs £47,500–£67,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). That range is adjusted for Northern Ireland, where domestic building work typically costs around 14% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £47,500–£67,000 |
| Higher specification | £67,000–£84,000 |
What moves the price most:
- Scaffolding to three sides
- Roof tile matching
- Gable wall construction and finish
- Size of the rear dormer
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a hip-to-gable loft conversion in Lisburn?
The approval route for Lisburn is set by planning law in Northern Ireland. In Northern Ireland roof enlargements must be set back from the verges to be permitted development, so a hip-to-gable conversion usually needs planning permission.
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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical hip-to-gable loft conversion we handle:
- Roof extension and rear dormer
- Building control sign-off
- Staircase and fire-safe escape route
- Drawings and structural calculations
- Survey and planning check
- Gable wall built in brick or block and finished to match
How long does it take?
Allow 7 to 10 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Lisburn
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
We work across Lisburn and neighbouring areas such as Belfast, Newtownabbey and Newtownards. Postcodes we cover in Lisburn include BT27 and BT28.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about hip-to-gable loft conversions in Lisburn
How much does a hip-to-gable loft conversion cost in Lisburn?
In Lisburn, a hip-to-gable loft conversion typically costs £47,500–£67,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Do I need planning permission for a hip-to-gable loft conversion in Lisburn?
In Northern Ireland roof enlargements must be set back from the verges to be permitted development, so a hip-to-gable conversion usually needs planning permission.
Is a hip-to-gable better than a dormer?
On a hipped roof, a dormer alone often leaves too little space for stairs. Combining hip-to-gable with a rear dormer gives the most room.
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
How long does it take?
Typically 7 to 10 weeks on site.
Do you build hip-to-gable loft conversions in Lisburn?
Yes. We build hip-to-gable loft conversions across Lisburn, including postcodes BT27 and BT28. Every project starts with a free home visit.