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 Bromley?
In Bromley, 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 Bromley 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 biggest cost drivers are:
- Gable wall construction and finish
- Roof tile matching
- Size of the rear dormer
- Scaffolding to three sides
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a hip-to-gable loft conversion in Bromley?
Here is how the rules work for a hip-to-gable loft conversion 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
On a typical hip-to-gable loft conversion we handle:
- Drawings and structural calculations
- Staircase and fire-safe escape route
- Insulation, electrics, plumbing and plastering
- Building control sign-off
- Survey and planning check
- Gable wall built in brick or block and finished to match
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 Bromley
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
Our Bromley coverage includes postcode districts BR1, and we also work in nearby places such as Beckenham, Catford and Eltham.
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 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 Bromley
Do you build hip-to-gable loft conversions in Bromley?
Yes. We build hip-to-gable loft conversions across Bromley, including postcodes BR1. Every project starts with a free home visit.
How long does it take?
Typically 7 to 10 weeks on site.
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.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
How much does a hip-to-gable loft conversion cost in Bromley?
In Bromley, 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.
