What Is a Mansard Roof?

The mansard roof is a ubiquitous feature in American Second Empire houses built between 1860 and 1890; in fact, the Second Empire style is often called the Mansard Style.

It was French architect François Mansart (1598 – 1666) who came up with a new way to squeeze more living space into a house without increasing the technical number of stories in the structure: he devised a four-sided, double slope gambrel roof punctuated with windows on the steeper lower slope, creating habitable space in the garrets.

This was an appealing solution in a city like Paris, where additional stories in buildings were restricted or heavily taxed. Eventually, Monsieur Mansart’s roof design was called the mansard roof.

The mansard roof is also found atop Richardson Romanesque and Beaux-Arts buildings, and it is often used as an accent feature in Queen Anne or Stick-Style houses, where a gabled roof may be accompanied by a mansard-roofed tower. Late 19^th century Americans were enamored of all things French, and they wanted to spend newly minted post-Civil War fortunes on flashy houses. Mansard roofs were very French and very flashy.

The top of a mansard roof is usually broad and flat to best maximize the volume of space beneath it—think of a hipped roof with its top surface spreading almost to the edges of the building. The lower pitch may be convex (outwardly curving, possibly in an S or bell shape,) concave (inwardly curved or flaring,) or steeply angled. Sometimes the mansard roof is two stories high.

Whatever the exact shape of the roof, there are always numerous dormer windows to light the living space within. Often, the cedar or slate shingles of a mansard roof wear a decorative belt course of differently colored or patterned shingles.

The first Second Empire building in the United States is the Renwick Gallery in Washington, D.C., completed in 1859 (featured in the picture above). It is now part of the Smithsonian Institution Museum of American Art and is a thoroughly imposing and elaborate exemplar of the style.

Although most Second Empire houses were grand affairs, the mansard roof also added heft and dignity to one-story cottages while increasing the living space. Today, Second Empire cottages abound, especially in the Northeast, where they are among America’s most beloved historical house styles.

The mansard roof gave way to flat roofs as early 20^th Americans adopted modern styles like Walter Gropius’s International style, with its severe lack of ornamentation. But everything comes back. Today’s homeowners are rediscovering it as a French accent that adds living space, and are putting them on new suburban houses that have nothing to do with the 19^th century.