 The mixed-use building was constructed in 1981 with parking on the second and third underground levels and retail space street and concourse levels topped by an eight-storey office block that rises to 14 floors on the east end of the site and 13 on the west.As part of downtown Toronto's PATH network, Atrium's Concourse Level is directly connected underground to the Dundas subway station, the Toronto Eaton Centre south, across on Dundas Street, and the Toronto Coach Terminal located west, across Bay Street.In 2011, H&R Real Estate Investment Trust purchased the property from Hines Interests Limited Partnership who acquired it in 2007 from a joint venture of Brookfield Properties and The Ellman Companies.