Mansard Roof

A mansard or mansard roof (also called a French roof) is a four-sided gambrel-style hip roof characterized by two slopes on each of its sides with the lower slope, punctured by dormer windows, at a steeper angle than the upper. The roof creates an additional floor of habitable space, such as a garret. The upper slope of the roof may not be visible from street level when viewed from close proximity to the building.

The roof design was first popularised by François Mansart (1598–1666), an accomplished architect of the French Baroque period. It became especially fashionable during the Second French Empire (1852–1870) of Napoléon III.