Mansard roofs have four sloping sides, like a hipped roof, and each side has a shallow slope over a steep slope, similar to a gambrel roof. There are almost always dormers in a mansard roof. Mansard is named after the French architect Francois Mansart (1598-1666), who was known to use this style of roof. This roof style was particularly popular in the latter half of the 19th century, and is often seen on Victorian row houses.
Check out the original article here