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 Northamptonshire?
In Northamptonshire, a hip-to-gable loft conversion typically costs £52,000–£74,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). The guide for Northamptonshire reflects typical costs in the East Midlands, roughly 5% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £52,000–£74,000 |
| Higher specification | £74,000–£92,500 |
Your quote will depend mainly on:
- Bathroom and plumbing
- Size of the rear dormer
- Staircase design
- Gable wall construction and finish
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 Northamptonshire?
Before anything is built in Northamptonshire, 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a hip-to-gable loft conversion:
- Roof extension and rear dormer
- Building control sign-off
- Drawings and structural calculations
- Insulation, electrics, plumbing and plastering
- Steel beams and floor joists
- Gable wall built in brick or block and finished to match
How long does it take?
Build time is typically 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 Northamptonshire
The East Midlands has a mix of red-brick terraces, inter-war semis and newer estates, so rear extensions and garage conversions are common projects.
Towns we cover in Northamptonshire include Northampton, Corby, Kettering, Wellingborough, Rushden and Daventry.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about hip-to-gable loft conversions in Northamptonshire
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 Northamptonshire?
Planning matters in Northamptonshire go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
How much does a hip-to-gable loft conversion cost in Northamptonshire?
In Northamptonshire, a hip-to-gable loft conversion typically costs £52,000–£74,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
How long does it take?
Typically 7 to 10 weeks on site.