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 Heywood?
In Heywood, a mansard loft conversion typically costs £61,000–£89,500 for a typical rear mansard, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the North West, where labour and materials are typically about 6% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £61,000–£89,500 |
| Higher specification | £89,500–£112,000 |
What moves the price most:
- Scaffolding on busy streets
- Front, rear or both
- Roof covering: natural slate costs more
- Number of dormers and lead work
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 Heywood?
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.
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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
The work we manage on a mansard loft conversion:
- Planning drawings and application
- Building control sign-off
- Staircase and fire-safe escape route
- Dormer windows
- New roof structure, slate or tile covering and lead work
- Structural design and calculations
How long does it take?
Build time is typically 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 Heywood
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
From OL10 outwards, we take on projects throughout Heywood and the surrounding parts of Greater Manchester.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Heywood
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
What roof covering is used?
Natural slate is traditional; some councils accept other materials. We follow local guidance.
How much does a mansard loft conversion cost in Heywood?
In Heywood, a mansard loft conversion typically costs £61,000–£89,500 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 Heywood?
Planning matters in Heywood go to the council covering your address, and the work needs building control approval. 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.