In 1993, the roof was ornamented with seven large, painted aluminum acroteria designed by Kent Bloomer with owl figures by Raymond Kaskey. The acroterium on the State Street side depicts an owl, the Greek symbol of knowledge. The acroteria on the Congress Parkway and on the Van Buren sides contain seed pods, which represent the natural bounty of the Midwest. The acroteria angularia each contain an owl perched in foliage.
(An acroterion or acroterium is an architectural ornament placed on a flat base called the acroter or plinth, and mounted at the apex of the pediment of a building in the Classical style. It may also be placed at the outer angles of the pediment; such acroteria are referred to as acroteria angularia. The acroterion may take a wide variety of forms, such as a statue, tripod, disc, urn, palmette or some other sculpted feature. Acroteria are also found in gothic architecture.The word comes from the Greek ἀκρωτήριον 'summit'; it was Latinized by the Romans as acroterium)
The exterior evokes the design of the Rookery, Auditorium and the Monadnock buildings. The bottom portion is made of large granite blocks. Red brick makes up the majority of the exterior. These two portions draw on the Beaux-Art style.
The pediments and most of the west side facing Plymouth Court are glass, steel and aluminum with ornamentation hearkening to the Mannerist style.
On the divide between the granite blocks and the brick portions are wall medallions that have the face of Ceres and ears of corn.
On the north, east and south sides of the build are five story tall arched windows. Between the windows are rope friezes.