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 Derry?
In Derry, 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). Building costs in Northern Ireland run about 14% below the UK average, and the figures for Derry are adjusted to reflect that. 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 |
The biggest cost drivers are:
- Staircase design
- Roof tile matching
- Scaffolding to three sides
- Bathroom and plumbing
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a hip-to-gable loft conversion in Derry?
The approval route for Derry 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most hip-to-gable loft conversions:
- Steel beams and floor joists
- Gable wall built in brick or block and finished to match
- Roof extension and rear dormer
- Survey and planning check
- Drawings and structural calculations
- Staircase and fire-safe escape route
How long does it take?
Expect 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Derry
Across Northern Ireland, bungalows and chalet bungalows are common, so loft conversions and rear extensions are popular projects.
From BT47 outwards, we take on projects throughout Derry and the surrounding parts of County Londonderry.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about hip-to-gable loft conversions in Derry
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
Who approves a hip-to-gable loft conversion in Derry?
Planning matters in Derry go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
How much does a hip-to-gable loft conversion cost in Derry?
In Derry, 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 Derry?
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.
How long does it take?
Typically 7 to 10 weeks on site.