Jack Diamond and Donald Schmitt have been the lead principals of this large firm for 33 years, and while they can take credit for many buildings in the Toronto area, it's probably the new opera house they are best known for. Completed in 2006, the Four Seasons Centre for the Performing Arts at the corner of Queen and University is not exactly radical, but it has some elegant qualities. The focus is the five-storey glazed wall that faces onto University Avenue and the glass staircase that fills the main vestibule. But the building, clad in iron-spot brick, seems mute and silent in comparison. Understated sophistication is characteristic of Diamond + Schmitt's projects: among their recent projects are First Waterfront Place (Corus Entertainment's new headquarters on the waterfront) and the über-sustainable campus for the University of Ontario Institute of Technology in Oshawa, which is up for LEED gold certification. As part of the team revitalizing the Don Valley Brick Works Factory, they designed the only new building, which features a changeable exterior skin and many sustainable elements. Occasionally, D+S ventures into residential, but public institutions are their main focus.