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 Pinner?
In Pinner, 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). The guide for Pinner reflects typical costs in London, roughly 30% above the UK-wide figure. 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:
- Scaffolding to three sides
- Gable wall construction and finish
- Size of the rear dormer
- 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 Pinner?
Before anything is built in Pinner, we confirm which approvals apply 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
The work we manage on a hip-to-gable loft conversion:
- Staircase and fire-safe escape route
- Gable wall built in brick or block and finished to match
- Roof extension and rear dormer
- Steel beams and floor joists
- Building control sign-off
- Drawings and structural calculations
How long does it take?
Expect 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Pinner
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
From HA5 outwards, we take on projects throughout Pinner and the surrounding parts of Greater London.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Pinner
Who approves a hip-to-gable loft conversion in Pinner?
Planning matters in Pinner go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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 Pinner?
In Pinner, 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.
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.
