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 Broxburn?
In Broxburn, a mansard loft conversion typically costs £63,000–£92,000 for a typical rear mansard, including VAT at 20% (standard rate). Building costs in Scotland are close to the UK average, so the figures for Broxburn are close to our national guide. 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 |
The main things that change the cost:
- Bathrooms and finishes
- Number of dormers and lead work
- Roof covering: natural slate costs more
- 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 Broxburn?
Before anything is built in Broxburn, we confirm which approvals apply 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a mansard loft conversion:
- Insulation, electrics, plumbing and plastering
- New roof structure, slate or tile covering and lead work
- Staircase and fire-safe escape route
- Dormer windows
- Structural design and calculations
- Building control sign-off
How long does it take?
Expect 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 Broxburn
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.
From EH52 outwards, we take on projects throughout Broxburn and the surrounding parts of the Lothians.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about mansard loft conversions in Broxburn
How much does a mansard loft conversion cost in Broxburn?
In Broxburn, 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.
Who approves a mansard loft conversion in Broxburn?
Planning matters in Broxburn go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
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.
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 Broxburn?
In Scotland a mansard needs planning permission and a building warrant.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
