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 Trowbridge?
In Trowbridge, a hip-to-gable loft conversion typically costs £56,000–£79,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Building costs in the South West are close to the UK average, so the figures for Trowbridge are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £56,000–£79,500 |
| Higher specification | £79,500–£99,500 |
What moves the price most:
- Gable wall construction and finish
- Roof tile matching
- Size of the rear dormer
- Staircase design
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 Trowbridge?
The approval route for Trowbridge is set by planning law in England. In England a hip-to-gable conversion is often permitted development within the 50 cubic metre roof volume limit for semi-detached and detached houses, provided the gable does not face a road and the house is not in a conservation area.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued 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
From survey to sign-off, the job normally involves:
- Drawings and structural calculations
- Gable wall built in brick or block and finished to match
- Staircase and fire-safe escape route
- Insulation, electrics, plumbing and plastering
- Building control sign-off
- Steel beams and floor joists
How long does it take?
Allow 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Trowbridge
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Our Trowbridge coverage includes postcode districts BA14, and we also work in nearby places such as Melksham, Bath and Frome.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 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 Trowbridge
How long does a hip-to-gable loft conversion take in Trowbridge?
Typically 7 to 10 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
Will it look strange next to my neighbour?
On a pair of semis the roofs will no longer match unless your neighbour does the same. Many streets already have several converted roofs.
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 much does a hip-to-gable loft conversion cost in Trowbridge?
In Trowbridge, a hip-to-gable loft conversion typically costs £56,000–£79,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.