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 Lancaster?
In Lancaster, 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). Building costs in the North West run about 6% below the UK average, and the figures for Lancaster 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 | £51,500–£73,500 |
| Higher specification | £73,500–£92,000 |
The biggest cost drivers are:
- Size of the rear dormer
- Roof tile matching
- Gable wall construction and finish
- Scaffolding to three sides
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 Lancaster?
Whether you need planning permission depends on your house and its location 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
From survey to sign-off, the job normally involves:
- Gable wall built in brick or block and finished to match
- Building control sign-off
- Roof extension and rear dormer
- Steel beams and floor joists
- Insulation, electrics, plumbing and plastering
- Survey and planning check
How long does it take?
Allow 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 Lancaster
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
From LA1 outwards, we take on projects throughout Lancaster and the surrounding parts of Lancashire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 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 Lancaster
How long does it take?
Typically 7 to 10 weeks on site.
Who approves a hip-to-gable loft conversion in Lancaster?
Planning matters in Lancaster go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
How much does a hip-to-gable loft conversion cost in Lancaster?
In Lancaster, 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.
