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.
Hip-to-gable conversions suit 1930s semis and detached houses with hipped roofs, where the loft is otherwise too small. They are often possible under permitted development, subject to roof volume limits.
What we handle
- Survey and planning check
- Drawings and structural calculations
- Gable wall built in brick or block and finished to match
- Roof extension and rear dormer
- Steel beams and floor joists
- Staircase and fire-safe escape route
- Insulation, electrics, plumbing and plastering
- Building control sign-off
Options to consider
Hip-to-gable with rear dormer
The most common combination, giving the most usable floor space.
Brick or render gable
The gable is finished to match the house, in brick, render or tile hanging.
Double hip-to-gable
On a detached house with two hips, both sides can be converted.
Bathroom in the loft
A shower room or en-suite under the new ridge.
How much does a hip-to-gable loft conversion cost?
A hip-to-gable loft conversion typically costs £55,000–£78,000 for a hip-to-gable with rear dormer across the UK, including VAT at 20% (standard rate). Build time is usually 7 to 10 weeks on site. Design, structural calculations and council fees are extra.
| Region | Guide range (for a hip-to-gable with rear dormer) |
|---|---|
| London | £71,500–£101,500 |
| South East | £61,500–£87,500 |
| East of England | £58,500–£82,500 |
| South West | £56,000–£79,500 |
| West Midlands | £53,500–£75,500 |
| East Midlands | £52,000–£74,000 |
| North West | £51,500–£73,500 |
| Yorkshire and the Humber | £51,000–£72,500 |
| North East | £49,500–£70,000 |
| Wales | £50,500–£72,000 |
| Scotland | £53,500–£75,500 |
| Northern Ireland | £47,500–£67,000 |
What changes the price:
- Gable wall construction and finish
- Size of the rear dormer
- Roof tile matching
- Bathroom and plumbing
- Scaffolding to three sides
- Staircase design
Use the guide price tool for a figure based on your measurements, or see all guide prices.
Do I need planning permission?
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.
Wales
In Wales a hip-to-gable conversion may be permitted development within roof volume limits; corner plots and conservation areas usually need permission.
Scotland
In Scotland changing a hipped roof to a gable often needs planning permission, because dormer and roof enlargement rights only apply well away from boundaries. A building warrant is needed before work starts.
Northern Ireland
In Northern Ireland roof enlargements must be set back from the verges to be permitted development, so a hip-to-gable conversion usually needs planning permission.
Even when planning permission is not needed, building regulations approval (a building warrant in Scotland) usually is. We make the applications and book the inspections.
How long does it take?
Typically 7 to 10 weeks on site. Surveys, design and approvals usually take 6 to 12 weeks beforehand.
How it works
- 01
Free visit
We look at the property, discuss what you want and measure up.
- 02
Design and fixed quote
Drawings, calculations and an itemised price for the agreed specification.
- 03
Approvals
Planning or permitted development, building regulations and neighbour matters.
- 04
Build and sign-off
Built to a written programme, with a completion certificate at the end.
Hip-to-gable loft conversions: questions and answers
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.
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.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
How long does it take?
Typically 7 to 10 weeks on site.
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
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.