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 Grantham?
In Grantham, 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). Building costs in the East Midlands run about 5% below the UK average, and the figures for Grantham 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 | £52,000–£74,000 |
| Higher specification | £74,000–£92,500 |
The main things that change the cost:
- Gable wall construction and finish
- Staircase design
- Bathroom and plumbing
- Roof tile matching
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a hip-to-gable loft conversion in Grantham?
Approvals for a hip-to-gable loft conversion in Grantham follow the rules for 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
From survey to sign-off, the job normally involves:
- Gable wall built in brick or block and finished to match
- Staircase and fire-safe escape route
- Building control sign-off
- Steel beams and floor joists
- Drawings and structural calculations
- Insulation, electrics, plumbing and plastering
How long does it take?
Allow 7 to 10 weeks on site. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Grantham
In the East Midlands, many estates built since the 1960s have integral garages that convert well into a study or bedroom.
Grantham sits in Lincolnshire, about 22 miles south of Lincoln. We cover the whole of Grantham, including postcodes NG31.
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 Grantham
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 long does a hip-to-gable loft conversion take in Grantham?
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.
How much does a hip-to-gable loft conversion cost in Grantham?
In Grantham, 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.
