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 Braintree?
In Braintree, a mansard loft conversion typically costs £69,000–£100,500 for a typical rear mansard, including VAT at 20% (standard rate). The guide for Braintree reflects typical costs in the East of England, roughly 6% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £69,000–£100,500 |
| Higher specification | £100,500–£125,500 |
The main things that change the cost:
- Front, rear or both
- Party wall surveyor fees
- Bathrooms and finishes
- 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 Braintree?
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.
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.
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:
- Structural design and calculations
- Dormer windows
- Party wall notices to both neighbours
- Staircase and fire-safe escape route
- Insulation, electrics, plumbing and plastering
- New roof structure, slate or tile covering and lead work
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 Braintree
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Braintree sits in Essex, about 10 miles north of Chelmsford. We cover the whole of Braintree, including postcodes CM7 and CM77.
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 pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about mansard loft conversions in Braintree
Who approves a mansard loft conversion in Braintree?
Planning matters in Braintree go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
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.
How much does a mansard loft conversion cost in Braintree?
In Braintree, a mansard loft conversion typically costs £69,000–£100,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.