What is a mansard loft conversion?

A mansard loft conversion rebuilds the roof with a nearly vertical slope (about 72 degrees) and a flat top, effectively adding a new storey. Small dormer windows sit within the steep slope. Mansards are common on period terraces in towns and cities.
How much does a mansard loft conversion cost in Pontypridd?
In Pontypridd, a mansard loft conversion typically costs £60,000–£87,500 for a typical rear mansard, including VAT at 20% (standard rate). Prices across Wales are typically 8% below the UK average for this kind of work, which is reflected in the range for Pontypridd. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £60,000–£87,500 |
| Higher specification | £87,500–£109,500 |
The main things that change the cost:
- Number of dormers and lead work
- Roof covering: natural slate costs more
- Front, rear or both
- Scaffolding on busy streets
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 mansard loft conversion in Pontypridd?
Approvals for a mansard loft conversion in Pontypridd follow the rules for Wales. In Wales a mansard roof needs planning permission and is judged against local design guidance.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most mansard loft conversions:
- Staircase and fire-safe escape route
- Party wall notices to both neighbours
- Planning drawings and application
- Structural design and calculations
- New roof structure, slate or tile covering and lead work
- Insulation, electrics, plumbing and plastering
How long does it take?
Build time is typically 9 to 12 weeks on site, after planning approval. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Pontypridd
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
Pontypridd sits in Mid Glamorgan, about 12 miles north-east of Bridgend. We cover the whole of Pontypridd, including postcodes CF37.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about mansard loft conversions in Pontypridd
How long does it take?
Around 9 to 12 weeks on site, plus 2 to 3 months for planning and party wall matters beforehand.
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
Who approves a mansard loft conversion in Pontypridd?
Planning matters in Pontypridd go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Do I need planning permission for a mansard loft conversion in Pontypridd?
In Wales a mansard roof needs planning permission and is judged against local design guidance.
How much does a mansard loft conversion cost in Pontypridd?
In Pontypridd, a mansard loft conversion typically costs £60,000–£87,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
