Mansard loft conversions generally have the party wall (shared with your neighbour) raised, have a flat roof with the back wall sloping inwards at an angle of 72 degrees. An L shaped mansard conversion can be achieved on Edwardian/ Victorian houses and flats to achieve a better use of space where the mansard is extending over the existing rear addition/ outrigger. This additional space can be used for a variety of different rooms – an additional bedroom, separate bathroom, larger ensuite, dressing room or a study.