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 Altrincham?
In Altrincham, a hip-to-gable loft conversion typically costs £51,500–£73,500 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 the North West, where labour and materials are typically about 6% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £51,500–£73,500 |
| Higher specification | £73,500–£92,000 |
The biggest cost drivers are:
- Bathroom and plumbing
- Gable wall construction and finish
- Staircase design
- Roof tile matching
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a hip-to-gable loft conversion in Altrincham?
Here is how the rules work for a hip-to-gable loft conversion 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
From survey to sign-off, the job normally involves:
- Insulation, electrics, plumbing and plastering
- Drawings and structural calculations
- Gable wall built in brick or block and finished to match
- Steel beams and floor joists
- Roof extension and rear dormer
- Staircase and fire-safe escape route
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 Altrincham
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Our Altrincham coverage includes postcode districts WA14, and we also work in nearby places such as Sale, Urmston and Stretford.
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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about hip-to-gable loft conversions in Altrincham
Is a hip-to-gable conversion permitted development?
Often yes in England, within the 50 cubic metre roof volume limit for semi-detached and detached houses. It is not permitted development in conservation areas or where rights have been removed.
How much does a hip-to-gable loft conversion cost in Altrincham?
In Altrincham, a hip-to-gable loft conversion typically costs £51,500–£73,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
How long does a hip-to-gable loft conversion take in Altrincham?
Typically 7 to 10 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
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.
