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 Luton?
In Luton, a hip-to-gable loft conversion typically costs £58,500–£82,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Prices across the East of England are typically 6% above the UK average for this kind of work, which is reflected in the range for Luton. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £58,500–£82,500 |
| Higher specification | £82,500–£103,000 |
The main things that change the cost:
- Size of the rear dormer
- Gable wall construction and finish
- Scaffolding to three sides
- Roof tile matching
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 Luton?
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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most hip-to-gable loft conversions:
- Steel beams and floor joists
- Gable wall built in brick or block and finished to match
- Drawings and structural calculations
- Insulation, electrics, plumbing and plastering
- Survey and planning check
- Building control sign-off
How long does it take?
Build time is typically 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 Luton
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
From LU1 outwards, we take on projects throughout Luton and the surrounding parts of Bedfordshire.
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 Luton
How much does a hip-to-gable loft conversion cost in Luton?
In Luton, a hip-to-gable loft conversion typically costs £58,500–£82,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
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.
Do you build hip-to-gable loft conversions in Luton?
Yes. We build hip-to-gable loft conversions across Luton, including postcodes LU1. Every project starts with a free home visit.
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.
