Situated in downtown Iowa City near the University of Iowa, this 575,000 square-foot mixed-use development includes a 12-story Hyatt Place hotel and 14-story residential building rising above the same two-story parking podium. The building features a large outdoor amenity deck on the 4th floor with a pool, plantings, outdoor kitchen and gathering spaces. A large public plaza over parking on the first floor provides access to the hotel and residential lobbies via a large exterior stair. All levels consist of post-tensioned concrete flat slabs supported by concrete columns and shear walls. Sloping grades cover the site, requiring the building’s lateral system to be designed to resist three stories of unbalanced soil at the lower levels. The PE team worked closely with the architect, general contractor, and geotechnical engineer to study multiple foundation options. The team ultimately selected a 5-foot-thick mat slab as the most economical foundation solution over a drilled pier deep foundation system.