He spent much of his career in the Montreal area, designing notable examples of Art Deco architecture, including the Université de Montréal original main building, the Supreme Court of Canada Building in Ottawa, and the Cormier House (his home in Montreal's Golden Square Mile).

Following his return to Paris in January 1917, he was employed by the engineering firm of Considère, Pelnard et Caquot, specialists in concrete, and he graduated as an architect of the French Government (DPLG).

Plans were laid out in 1948 but only completed in 1960, it is a massive cathedral-like building, originally designed as Quebec City's Grand Séminaire, which is particularly spectacular viewed from a distance along the impressive mall that runs along the east–west axis of the campus grounds.

[3] Despite an unfortunate renovation scheme in the 1970s, which gutted the chapel, filled in the magnificent enclosed courtyard and transformed the interior into an undecipherable labyrinth, the building has become the most recognized landmark of the second-oldest university in North America and home to Laval's faculties of Music and Communications, as well as to Quebec's National Archives (in the former church).

[citation needed] Former Canadian prime minister Pierre Trudeau purchased the building in 1979, and he lived there following his retirement until his death in 2000.

In 1974, Cormier was inducted into the Order of Canada by Governor General Jules Léger, and he received numerous honours and awards.