Located at 305 Rideau Street at the corner of King Edward, the building was used by the Department of National Defence (DND).

As of 2015, the building has been decommissioned and all sections of DND have been relocated.

Amenities at the building included a cafeteria, barber shop and convenience store, all of which were accessible to the general public as well as employees of the building.

[1] After significant renovations, the Constitution Building is, as of 2020, an all-inclusive student apartment building branded under the name Théo.

[2] This article relating to Ottawa and to Canada's National Capital Region is a stub.