Mansard loft conversions in Cornwall

Covering Cornwall

Our coverage across Cornwall includes Redruth, Falmouth, St Austell and Truro.

Because Cornwall covers a wide area, we confirm availability after the first call and include any travel costs in the written quote rather than adding them later.

Homes in the South West

The South West mixes stone and render cottages, Victorian terraces in the larger towns and modern estates, and many historic centres are conservation areas where materials and roof shapes are closely controlled.

What goes into a mansard loft conversion?

Mansards are a bigger structural job than other conversions because the roof is largely rebuilt. They normally need planning permission, and many councils have design guides setting the angle, materials and window style. We prepare the design to those guides and build in slate, lead and timber or approved alternatives.

Structural design and party wall process
Staircase, insulation and fit-out
En-suite, electrics and fire safety

How much should I budget for a mansard loft conversion?

Typical ranges for mansard loft conversions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

Mansard loft conversions	Guide price incl. VAT
Rear mansard	£65,000 to £85,000
Front and rear (double) mansard	£80,000 to £110,000

Do you need permission for a mansard loft conversion in Cornwall?

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

Mansard conversions change the shape of the roof significantly, so they usually need planning permission in England.

What can affect a mansard loft conversion?

A mansard nearly always involves party walls on both sides of a terrace.
Council design guides often require natural slate and lead.

What happens after I enquire?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

What people ask before starting

Does a mansard need planning permission?

Almost always, because it changes the roof profile.

How long does a mansard take?

Around 10 to 14 weeks on site after planning approval.

Do you work in Cornwall?

Yes. Cornwall is within our coverage for mansard loft conversions, along with nearby Redruth and Falmouth.

Mansard loft conversions near Cornwall

Learn more about mansard loft conversions, or see every project we cover in Cornwall.