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 St Helens?
In St Helens, a hip-to-gable loft conversion typically costs £51,500–£73,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the North West, where labour and materials are typically about 6% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £51,500–£73,500 |
| Higher specification | £73,500–£92,000 |
What moves the price most:
- Roof tile matching
- Scaffolding to three sides
- Staircase design
- Bathroom and plumbing
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 St Helens?
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Gable wall built in brick or block and finished to match
- Building control sign-off
- Survey and planning check
- Steel beams and floor joists
- Insulation, electrics, plumbing and plastering
- Roof extension and rear dormer
How long does it take?
The build itself usually takes 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 St Helens
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
From WA10 outwards, we take on projects throughout St Helens and the surrounding parts of Merseyside.
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 St Helens
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.
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.
Who approves a hip-to-gable loft conversion in St Helens?
Planning matters in St Helens go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a hip-to-gable loft conversion cost in St Helens?
In St Helens, a hip-to-gable loft conversion typically costs £51,500–£73,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
