Mansard Loft Conversion
Written by Administrator
Thursday, 13 January 2011 16:33

This type of conversion is generally designed within the inner London areas, where clients are following the Mansard trend of similar conversions within their locality.



A mansard is constructed by raising the party walls either side of your property in brick and then creating a timber frame between the two new walls. The rear face of the mansard should slope backwards at 72degrees to comply with planning requirements. 

Planning permission

Mansards will almost always require planning consent and full head-height floor space will be slightly less than in an equivalent sized dormer due to the slope of the mansard face.


 Mansard style conversions offer many of the same advantages as dormers, although are regarded by some to be more aesthetically pleasing, especially on older properties.


Mansard Loft cost a bit more than standard dormer loft, but offers better overall look to the house.

Price to convert you loft space into mansard style loft will range between £30,000 - £45,000.

It will include:

  • New floor joists;
  • Steel Beams to hold the weight of the floor;
  • One Ridge Steel Beam to hold the weight of the flat roof;
  • Unsuite Bathroom;
  • Two small front Dormer;
  • Two sash windows;
  • Two small back Dormers;
  • Two sash windows;
  • Two small radiators;
  • Loft stair to match existing;
  • One pendant light, one light switch, one double socket and smoke detector
  • Roof insulation to satisfy Building Regulations
  • Skim finish and decoration