Northwestern Medicine Oak Brook Outpatient Center

overview

Located on the corner of the Oak Brook Commons campus just west of Chicago, a new medical office building houses the Northwestern Medicine Oak Brook Outpatient Center. Featuring four floors of medical office space and three floors of parking, the facility offers immediate, primary and specialty care, as well as diagnostic imaging, physical therapy and a laboratory.

We provided structural design services to Antunovich Associates for the project. We also worked with the contractor and Northwestern Medicine's architect during construction, in part due to our knowledge of the base building structure, but also due to our responsiveness. 

highlights

• While we initially proposed using a steel structural system above the precast concrete parking garage, high steel prices led us to explore an entirely reinforced concrete structure. We ultimately went with a hybrid floor system of post-tensioned beams with one-way mild steel slabs between beams to provide the desired ceiling height for the column grid, flexibility for future floor penetrations and to meet the construction budget.
• Post-tensioned two-way slabs are used at the parking floors, and post-tensioned band beams with mild steel one-way slabs span between them at the office floors. 
• Mild steel slabs more easily accommodated the cores that the tenant required for the buildout and for future changes, providing resilience in a structural type that is often seen as difficult to modify.
• The overall floor plate height was also considerably shorter than the steel framing option, resulting in cost savings for the project.