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 the Lothians?
In the Lothians, a mansard loft conversion typically costs £63,000–£92,000 for a typical rear mansard, including VAT at 20% (standard rate). Prices in Scotland sit near the national average for this kind of work, and the range for the Lothians reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £63,000–£92,000 |
| Higher specification | £92,000–£115,000 |
What moves the price most:
- Bathrooms and finishes
- Number of dormers and lead work
- Front, rear or both
- Roof covering: natural slate costs more
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 the Lothians?
Whether you need planning permission depends on your house and its location in Scotland. In Scotland a mansard needs planning permission and a building warrant.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Staircase and fire-safe escape route
- Dormer windows
- Building control sign-off
- Written agreement with neighbours on shared walls
- Structural design and calculations
- Insulation, electrics, plumbing and plastering
How long does it take?
Allow 9 to 12 weeks on site, after planning approval. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in the Lothians
Scotland’s housing ranges from sandstone tenements and villas to post-war and modern estates, and the building warrant system shapes how projects are planned.
Towns we cover in the Lothians include Livingston, Musselburgh, Bathgate, Bonnyrigg, Penicuik and Broxburn.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about mansard loft conversions in the Lothians
What roof covering is used?
Natural slate is traditional; some councils accept other materials. We follow local guidance.
Do I need planning permission for a mansard loft conversion in the Lothians?
In Scotland a mansard needs planning permission and a building warrant.
How much does a mansard loft conversion cost in the Lothians?
In the Lothians, a mansard loft conversion typically costs £63,000–£92,000 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Do you build mansard loft conversions in the Lothians?
Yes. We build mansard loft conversions across the Lothians, including postcodes EH10, EH11, EH18, EH19 and EH20. Every project starts with a free home visit.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
Why choose a mansard over a dormer?
A mansard gives more usable floor space and a neater appearance from the street, but costs more and needs planning permission.
