Mansard Loft Conversion
Maximum Space, Premium Design
The ultimate loft conversion. Near-vertical walls create maximum usable space—effectively adding a full new floor to your home.
A Full Floor, Not Just a Room
A mansard conversion transforms your entire roof, creating near-vertical (72°) walls and a flat top. The result? Maximum usable floor space—often enough for multiple bedrooms, bathrooms, and storage.
Popular in conservation areas across London where the clean lines blend with Georgian and Victorian architecture. Yes, planning permission is usually required—but we handle the entire process.
- Maximum floor space from your loft
- Multiple rooms possible
- From £70,000 fully fitted
- Adds significant property value
Is a Mansard Conversion Right For You?
✓ Ideal When...
- You want maximum space from your loft
- Multiple rooms or en-suites are needed
- Your property has a flat or butterfly roof
- You're willing to go through planning
- Adding a full floor makes financial sense
✗ Consider Alternatives When...
- Budget is the primary concern
- You only need one small room
- Planning permission is unlikely (check with us)
- Speed is critical—mansards take longer
- Neighbours have had applications refused
What's Included
Complete Roof Rebuild
New roof structure with zinc/slate finish
Dormer Windows
Full-height windows across rear elevation
Steel Structure
Structural steel beams for open-plan layouts
Plumbing for En-Suite
Full wet room capability included
Electrics & Heating
Full electrical & radiator installation
Planning & Building Regs
Full application and approval management
Mansard Loft Conversion Questions
Mansard loft conversions in London typically cost from £70,000-£120,000+ depending on size, specification, and location. This reflects the extensive structural work involved. We provide detailed, fixed-price quotes.
Yes—mansard conversions almost always require planning permission because they significantly alter the roof structure. We have extensive experience obtaining approvals across London boroughs and handle the entire process.
Construction typically takes 10-14 weeks. However, planning permission can add 8-12 weeks before work begins. We advise factoring in 6-9 months total from initial consultation to moving in.
Book Your Free Survey
We'll assess your property and explain whether a mansard is right for you—with an honest planning likelihood assessment.