The distinctive look of Michael Graves' Portland Building, with its use of a variety of surface materials and colors, small windows, and inclusion of prominent decorative flourishes, was in stark contrast to the architectural style most commonly used for large office buildings at the time,[7] and made the building an icon of postmodern architecture. It is the first major postmodern building, opening before Philip Johnson's AT&T Building, and its design has been described as a rejection of the Modernist principles established in the early 20th century. Graves' design was selected in a large design competition, with Johnson as one of the three members of the selection committee. Graves was added into the competition after Johnson threw out the entry from architect Gunnar Birkerts for having not been Postmodern enough. Birkerts went on to design the Detroit Institute of Arts South Wing, which was re-clad by Graves in 2007.