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 Barnet?
In Barnet, a hip-to-gable loft conversion typically costs £71,500–£101,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for London, where labour and materials are typically about 30% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £71,500–£101,500 |
| Higher specification | £101,500–£127,000 |
The main things that change the cost:
- Size of the rear dormer
- Bathroom and plumbing
- Gable wall construction and finish
- Roof tile matching
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a hip-to-gable loft conversion in Barnet?
The approval route for Barnet 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical hip-to-gable loft conversion we handle:
- Roof extension and rear dormer
- Staircase and fire-safe escape route
- Drawings and structural calculations
- Steel beams and floor joists
- Building control sign-off
- Survey and planning check
How long does it take?
Expect 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 Barnet
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Barnet sits in Greater London, about 10 miles north of central London. We cover the whole of Barnet, including postcodes EN5.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about hip-to-gable loft conversions in Barnet
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
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 a hip-to-gable loft conversion take in Barnet?
Typically 7 to 10 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a hip-to-gable loft conversion cost in Barnet?
In Barnet, a hip-to-gable loft conversion typically costs £71,500–£101,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.