Built in 1885 and previously a private residence, the building is now home to the Centre for Drama, Theatre and Performance Studies (CDTPS) and the Commuter Student Centre. The Union also provides rehearsal space, boardrooms and reception and meetings rooms.
Named in honour of a University of Toronto alumna and CDTPS benefactor, the Helen Gardiner Phelan Playhouse is located on the second floor of the Union building. Used primarily by the Centre for Drama, Theatre & Performance Studies, the theatre is equipped with professional lighting and sound installations.
Located on the main floor of the Union (UC Union), the Walden Room offers a centrally located boardroom for use by the University of Toronto community and external groups.
The front and long rooms are adjacent formal living rooms located on the main floor of the Union building. The spaces are used to host meetings and receptions given by the University of Toronto community, but can also be booked by external groups.