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 Merthyr Tydfil?
In Merthyr Tydfil, a hip-to-gable loft conversion typically costs £50,500–£72,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). The guide for Merthyr Tydfil reflects typical costs in Wales, roughly 8% 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 | £50,500–£72,000 |
| Higher specification | £72,000–£90,000 |
Your quote will depend mainly on:
- Staircase design
- Bathroom and plumbing
- Scaffolding to three sides
- Gable wall construction and finish
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 Merthyr Tydfil?
The approval route for Merthyr Tydfil is set by planning law in Wales. In Wales a hip-to-gable conversion may be permitted development within roof volume limits; corner plots and conservation areas usually need permission.
Building regulations in Wales are set by the Welsh Government. Approval comes from the council’s building control service or a registered building control approver, with inspections during the work and a completion certificate 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
What we take care of:
- Insulation, electrics, plumbing and plastering
- Building control sign-off
- Drawings and structural calculations
- Roof extension and rear dormer
- Survey and planning check
- 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 Merthyr Tydfil
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
From CF47 outwards, we take on projects throughout Merthyr Tydfil and the surrounding parts of Mid Glamorgan.
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 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 Merthyr Tydfil
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 long does it take?
Typically 7 to 10 weeks on site.
How much does a hip-to-gable loft conversion cost in Merthyr Tydfil?
In Merthyr Tydfil, a hip-to-gable loft conversion typically costs £50,500–£72,000 for a hip-to-gable with rear dormer, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Who approves a hip-to-gable loft conversion in Merthyr Tydfil?
Planning matters in Merthyr Tydfil go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can the gable be brick?
Yes. We match the existing finish, whether brick, render or pebbledash.
Do I need planning permission for a hip-to-gable loft conversion in Merthyr Tydfil?
In Wales a hip-to-gable conversion may be permitted development within roof volume limits; corner plots and conservation areas usually need permission.
