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 Portsmouth?
In Portsmouth, 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). The guide for Portsmouth reflects typical costs in the South East, roughly 12% 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 | £61,500–£87,500 |
| Higher specification | £87,500–£109,500 |
The biggest cost drivers are:
- Roof tile matching
- Scaffolding to three sides
- Bathroom and plumbing
- Size of the rear dormer
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 Portsmouth?
The approval route for Portsmouth is set by planning law 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
On a typical hip-to-gable loft conversion we handle:
- Staircase and fire-safe escape route
- Steel beams and floor joists
- Building control sign-off
- Roof extension and rear dormer
- Drawings and structural calculations
- Insulation, electrics, plumbing and plastering
How long does it take?
Expect 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 Portsmouth
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
Projects in Portsmouth (PO5) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Portsmouth
How much does a hip-to-gable loft conversion cost in Portsmouth?
In Portsmouth, 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.
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.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
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.
Who approves a hip-to-gable loft conversion in Portsmouth?
Planning matters in Portsmouth go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.