Mansart studied under his great uncle François Mansart, also a renown architect.
Among his most well-known works are the Pont-Royal, Eglise du Dome, L'Eglise de Saint-Louis-des-Invalides, the Place Vendôme and the Place des Victoires. Most of these works can be seen by a modern-day tourist in Paris.
He also helped design a large part of the Palace of Versailles for King Louis XIV of France, including the North and South wings, the Royal Chapel, and the celebrated Hall of Mirrors. Outside of the chateau proper he built the Grand Trianon and the Orangerie. Mansart's work is considered by many to be the apex of Baroque architecture, representing the power and grandeur of Louis XIV.
Mansart is often considered one of the most important archtiects of the 17th century.
The mansard roof, named after Mansart, is a roof with two slopes on all four sides, with the lower slope nearly vertical and the upper nearly horizontal. It is a common feature in many pre-20th century buildings in Europe and North America.