A Mansard roof is a four-sided roof design characterized by two slopes on each side. The lower slope is steeper, while the upper slope is more gentle. This unique structure allows for additional living space in the attic, making it a popular choice for residential buildings, especially in the French architectural style. The design originated in the 16th century and is named after the architect François Mansart. Mansard roofs are often seen in Victorian and Second Empire styles, providing a distinctive silhouette that enhances the aesthetic appeal of a building while maximizing usable space.