The prolific architectural firm of Smith, Hinchman and Grylls, now SmithGroup, consolidated its scattered operations into this headquarters in downtown Detroit. Designed in 1910 by the firm for commercial use, the Cass Building was acquired by the firm, stripped to its reinforced-concrete frame, and rebuilt for contemporary use as its own offices. The exterior wall system on the north and west elevations is sheathed in 5 × 3–foot, bronze-tinted glass panes that are seated in aluminum mullions, held in place with silicone sealant, and decorated at each corner by giant, cast-aluminum spider clamps that conceal the intersections of the aluminum frame.