Mansard Loft Conversions

A Mansard loft conversion involves opening up one or more sides of the roof and adding two walls in its place. While the angles aren’t quite 90 degrees, the standard is around 70 degrees so the internal space is more of a standard square rather than the triangular shape associated with loft conversions.

Mansard loft conversions offer the most spacious rooms out of all loft conversion types. Due to the size, you can either add more rooms to the space or simply enjoy one larger room.


There are a lot of benefits to building a Mansard conversion, including:

  • Larger rooms
  • Square/rectangular shaped rooms
  • More than two vertical (or almost vertical) walls
  • Easy to fit a fully-integrated staircase
  • More head room
  • Easier to decorate and furnish
  • Less unusable floor space


However, these benefits to come at a cost:

  • Planning permission is required
  • More expensive than other loft conversion types
  • Longer build time than other loft conversion types
  • Some areas have restrictions on this type of loft conversion

What Else You Need to Know

If you would like to create even more space in your loft, a double Mansard conversion opens up both sides of the roof and adds the Mansard onto both sides. This gives you an even larger square space and completely changes both sides of the roof. In some cases there may be restrictions on changing the front aspect of your roof, so even with planning permission it may be difficult to gain a double Mansard conversion.

If you have any questions about building a Mansard conversion, just get in touch. Our experienced team is happy to answer any of your questions and conduct a free assessment so that you know the exact costs for your project. The assessment also allows us to see the space and make recommendations based on our experience.

For more information or advice
Call 07944 187 012