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 Austell?
In St Austell, a hip-to-gable loft conversion typically costs £56,000–£79,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Building costs in the South West are close to the UK average, so the figures for St Austell are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £56,000–£79,500 |
| Higher specification | £79,500–£99,500 |
What moves the price most:
- Bathroom and plumbing
- Scaffolding to three sides
- Roof tile matching
- Staircase design
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a hip-to-gable loft conversion in St Austell?
The approval route for St Austell 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.
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
The work we manage on a hip-to-gable loft conversion:
- Gable wall built in brick or block and finished to match
- Steel beams and floor joists
- Drawings and structural calculations
- Insulation, electrics, plumbing and plastering
- Roof extension and rear dormer
- Survey and planning check
How long does it take?
The build itself usually takes 7 to 10 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in St Austell
The South West mixes stone and render cottages with post-war and newer estates, and local materials matter more here when matching an extension.
We work across St Austell and neighbouring areas such as Truro, Newquay and Falmouth. Postcodes we cover in St Austell include PL25.
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
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about hip-to-gable loft conversions in St Austell
How long does a hip-to-gable loft conversion take in St Austell?
Typically 7 to 10 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
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.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
Will I need building regulations approval?
Yes. All loft conversions to habitable rooms need building control approval for structure, fire safety, insulation and stairs.
How much does a hip-to-gable loft conversion cost in St Austell?
In St Austell, a hip-to-gable loft conversion typically costs £56,000–£79,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.