Mansard loft conversions in Grantham

Covering Grantham

Alongside Grantham, we also cover Newark-on-Trent, Melton Mowbray (14 miles to the south-west) and Oakham.

Homes in the East Midlands

The East Midlands combines red-brick terraces in the cities with a lot of post-war and modern estate housing, so rear extensions, garage conversions and loft conversions are all common.

What goes into a mansard loft conversion?

A mansard loft conversion replaces one or both slopes of a roof with a near-vertical wall, typically at 70 degrees, with small dormer windows set into it. It creates almost a full extra storey and is common on terraced houses in towns and cities, particularly in London.

Structural design and party wall process
Roof removal and new mansard frame
En-suite, electrics and fire safety

How much does a mansard loft conversion cost in Grantham?

Use these ranges to budget for mansard loft conversions; the survey turns them into a fixed price for the agreed specification.

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

What approvals does a mansard loft conversion need in England?

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. Many councils publish guidance on mansard design.

What should Grantham homeowners check first?

A mansard nearly always involves party walls on both sides of a terrace.
The roof is open for longer than with a dormer, so weather protection matters.

From first call to completion

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Mansard loft conversions: common questions

How much does a mansard loft conversion cost?

Typically £65,000 to £110,000 including VAT, depending on whether one or both roof slopes are rebuilt.

How long does a mansard take?

Around 10 to 14 weeks on site after planning approval.

Who deals with the council for a project in Grantham?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Mansard loft conversions near Grantham

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