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 West Midlands?
In the West Midlands, a mansard loft conversion typically costs £63,000–£92,000 for a typical rear mansard, including VAT at 20% (standard rate). Building costs in the West Midlands are close to the UK average, so the figures for the West Midlands 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 biggest cost drivers are:
- Front, rear or both
- Scaffolding on busy streets
- Bathrooms and finishes
- Party wall surveyor fees
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 mansard loft conversion in the West Midlands?
Here is how the rules work for a mansard loft conversion in England. In England a mansard almost always needs planning permission because it changes the roof shape. Many councils publish design guidance for mansards on terraced streets, and some streets are more likely to be approved where neighbours already have one.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a mansard loft conversion:
- Dormer windows
- Structural design and calculations
- Party wall notices to both neighbours
- Staircase and fire-safe escape route
- Planning drawings and application
- New roof structure, slate or tile covering and lead work
How long does it take?
Build time is typically 9 to 12 weeks on site, after planning approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in the West Midlands
Across the West Midlands, inter-war and post-war semis make up much of the housing, giving good scope for two-storey side extensions and hip-to-gable lofts.
Towns we cover in the West Midlands include Birmingham, Coventry, Wolverhampton, Dudley, Walsall and Solihull.
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
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 West Midlands
What roof covering is used?
Natural slate is traditional; some councils accept other materials. We follow local guidance.
How long does a mansard loft conversion take in the West Midlands?
Typically 9 to 12 weeks on site, after planning approval. Design and approvals beforehand usually take 3 to 4 months.
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
How much does a mansard loft conversion cost in the West Midlands?
In the West Midlands, 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.