Career
After Napoleon"s exile he remained the assistant of Pierre François Léonard Fontaine, whose design for the sober Chapelle Expiatoire over the burial site of Louis XVI and Marie Antoinette he oversaw in construction (1816-1824). He also assisted Éloi Labarre (1764—1833) in completing the Palais Brongniart (1813-1826), the seat of the Paris Bourse, named after its architect, Alexandre Brongniart. He built the former prison of Petite Roquette, (1826-1836, demolished 1974), which was the first example in France of a progressive panoptic prison.
Lebas taught the History of Architecture at the École des Beaux-Arts, from 1840 to 1863.
In this teaching role, applying the art-historical method of Johann Joachim Winckelmann to the study of historical architecture, he set a mark on several generations of young French architects.