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 Worcester?
In Worcester, 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 Worcester 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:
- Scaffolding on busy streets
- Roof covering: natural slate costs more
- Number of dormers and lead work
- Front, rear or both
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 Worcester?
Whether you need planning permission depends on your house and its location 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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued 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
Handled as part of most mansard loft conversions:
- Building control sign-off
- Structural design and calculations
- New roof structure, slate or tile covering and lead work
- Party wall notices to both neighbours
- Dormer windows
- Insulation, electrics, plumbing and plastering
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 Worcester
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.
From WR1 outwards, we take on projects throughout Worcester and the surrounding parts of Worcestershire.
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 in place
We handle planning, building control and neighbour notices before work starts.
- 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 Worcester
Does a mansard need planning permission?
Almost always, because it changes the roof shape. Councils assess it against local design guidance.
How much does a mansard loft conversion cost in Worcester?
In Worcester, 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.
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 Worcester?
Typically 9 to 12 weeks on site, after planning approval. Design and approvals beforehand usually take 3 to 4 months.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
