The building, known today as Essex Hall, was constructed in two phases on what is now the campus of the University of Windsor. As an institution, Essex College was incorporated in 1954 as a non-denominational college. Two years later it became affiliated with Assumption University, assuming responsibility for the Faculty of Applied Science, the Schools of Business Administration and Nursing, and the Departments of Biology, Chemistry, Geology and Geography, Mathematics, and Physics. Phase 1, to the south, was known originally as the Pure and Applied Science Building and was completed in 1961.
The College became part of University of Windsor, when it was incorporated in 1962. Phase 2, to the north, was completed in 1964.
The college building has a symmetrical, rational plan configuration, flat roofs, and elevations that echo the structural frame. The frame is clad in a composition that includes brick veneer, smooth limestone panels, and curtain wall of anodized aluminum with black spandrels. Perhaps most distinctive are the free-standing entrance canopies of reinforced concrete, with their zig-zag profile. The armorial crests carved into the limestone panels lend an air of tradition to the otherwise modern design.
Essex College complemented the other modern buildings on the campus designed by Pennington and Carter: Leddy Library (1959), and University Centre (1962), which has since been demolished.
There have been subsequent additions to the rear of the building, that is, the east elevation.