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 Walton-on-Thames?
In Walton-on-Thames, a hip-to-gable loft conversion typically costs £61,500–£87,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Building costs in the South East run about 12% above the UK average, and the figures for Walton-on-Thames 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 | £61,500–£87,500 |
| Higher specification | £87,500–£109,500 |
Your quote will depend mainly on:
- Roof tile matching
- Size of the rear dormer
- Gable wall construction and finish
- Staircase design
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 Walton-on-Thames?
Before anything is built in Walton-on-Thames, 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
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
- Staircase and fire-safe escape route
- Drawings and structural calculations
- Roof extension and rear dormer
- Insulation, electrics, plumbing and plastering
How long does it take?
Expect 7 to 10 weeks on site. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Walton-on-Thames
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
Our Walton-on-Thames coverage includes postcode districts KT12, and we also work in nearby places such as Sunbury-on-Thames, Weybridge and Esher.
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
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 Walton-on-Thames
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
Do you build hip-to-gable loft conversions in Walton-on-Thames?
Yes. We build hip-to-gable loft conversions across Walton-on-Thames, including postcodes KT12. Every project starts with a free home visit.
How long does it take?
Typically 7 to 10 weeks on site.
How much does a hip-to-gable loft conversion cost in Walton-on-Thames?
In Walton-on-Thames, a hip-to-gable loft conversion typically costs £61,500–£87,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
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.
