Trowbridge originally housed dental science, which had moved from its first home (in Old Dental Building, razed in 1975) on the Pentacrest. With the relocation of the health sciences to the new Medical Campus on the western bluffs of the Iowa River, Trowbridge was freed up and reprogrammed for the Department of Geology in 1973. It was also named after Arthur C. Trowbridge, a longtime geology professor at the University.
Like other buildings on Main Campus North, Trowbridge Hall is faced in Flemish Bond brick with limestone detailing. While giving up the more noble (and expensive) materials of the Pentacrest, Trowbridge maintains the same Beaux-Arts stylistic orientation, as the Classical detailing shows. This is also apparent in the monumental scale of the brick-faced Doric pilasters paired at the entrance. These dominant pilasters add visual power to the façade, but the shift down to Doric from the elegant Ionic used in all the preceding Beaux-Arts campus buildings indicates a more modest architectural image. There are, however, a few oddities about the design that need explanation. The classically unacceptable asymmetry of the façade, with the entrance offset to the left, could be accounted for by an intended south wing with an equal number of bays to the left, which would have balanced the composition. The other unusual feature, the horizontal windows squeezed between the pilasters of the second and third floors (now altered with glass blocks and modern frames) are perhaps a concession to contemporary design of the day. The famous three-sectioned Chicago window, already popularized by Louis Sullivan (Carson-Pirie-Scott Department Store) and introduced to Iowa City on the 1904 Carnegie Public Library, seems to have made an impact here. It can be seen in the recessed third-floor window of the entrance bay and originally all along the north flank. The replacement of the side windows at a later date makes the appreciation of this feature difficult, but it marks the first hint of Modernism on the UI campus.
The building is accessible to persons with disabilities.