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 Mendip?
In Mendip, 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). Prices in the South West sit near the national average for this kind of work, and the range for Mendip reflects that. 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 |
Your quote will depend mainly on:
- Roof tile matching
- Bathroom and plumbing
- Scaffolding to three sides
- Size of the rear dormer
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 Mendip?
Before anything is built in Mendip, we confirm which approvals apply 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a hip-to-gable loft conversion:
- Insulation, electrics, plumbing and plastering
- Building control sign-off
- Roof extension and rear dormer
- Gable wall built in brick or block and finished to match
- Drawings and structural calculations
- Steel beams and floor joists
How long does it take?
The build itself usually takes 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Mendip
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Mendip sits in Somerset, about 26 miles north-east of Taunton. We cover the whole of Mendip, including postcodes BA5.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about hip-to-gable loft conversions in Mendip
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.
How much does a hip-to-gable loft conversion cost in Mendip?
In Mendip, 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.
Who approves a hip-to-gable loft conversion in Mendip?
Planning matters in Mendip go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
