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 Seaham?
In Seaham, a hip-to-gable loft conversion typically costs £49,500–£70,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Building costs in the North East run about 10% below the UK average, and the figures for Seaham 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 | £49,500–£70,000 |
| Higher specification | £70,000–£87,500 |
The biggest cost drivers are:
- Scaffolding to three sides
- Size of the rear dormer
- Staircase design
- Bathroom and plumbing
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 Seaham?
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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Roof extension and rear dormer
- Gable wall built in brick or block and finished to match
- Building control sign-off
- Staircase and fire-safe escape route
- Insulation, electrics, plumbing and plastering
- Steel beams and floor joists
How long does it take?
Build time is typically 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Seaham
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
Seaham sits in County Durham, about 10 miles north-east of Durham. We cover the whole of Seaham, including postcodes SR7.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about hip-to-gable loft conversions in Seaham
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 Seaham?
In Seaham, a hip-to-gable loft conversion typically costs £49,500–£70,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
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.
Who approves a hip-to-gable loft conversion in Seaham?
Planning matters in Seaham go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
