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 Twickenham?
In Twickenham, a hip-to-gable loft conversion typically costs £71,500–£101,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). That range is adjusted for London, where domestic building work typically costs around 30% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A hip-to-gable with rear dormer | £71,500–£101,500 |
| Higher specification | £101,500–£127,000 |
What moves the price most:
- Gable wall construction and finish
- Bathroom and plumbing
- Staircase design
- Scaffolding to three sides
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 Twickenham?
Whether you need planning permission depends on your house and its location 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
What we take care of:
- Staircase and fire-safe escape route
- Roof extension and rear dormer
- Gable wall built in brick or block and finished to match
- Survey and planning check
- Steel beams and floor joists
- Drawings and structural calculations
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 Twickenham
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
We work across Twickenham and neighbouring areas such as Teddington, Richmond and Kingston upon Thames. Postcodes we cover in Twickenham include TW1 and TW2.
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 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 Twickenham
Do you build hip-to-gable loft conversions in Twickenham?
Yes. We build hip-to-gable loft conversions across Twickenham, including postcodes TW1 and TW2. Every project starts with a free home visit.
How long does it take?
Typically 7 to 10 weeks on site.
How much does a hip-to-gable loft conversion cost in Twickenham?
In Twickenham, a hip-to-gable loft conversion typically costs £71,500–£101,500 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
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.
