Chicago Horizon

2015 | Chicago IL

Client Chicago Architecture Biennial
Architect and Design Collaborator Ultramoderne (Aaron Forrest and Yasmin Vobis)
Structural Engineer and Design Collaborator Guy Nordenson and Associates (Brett H Schneider)
Architect of Record Animate Architecture
Engineer of Record Thornton Tomasetti
Awards 2017 AIA | RI Design Honor Award; 2017 SEAoNY Excellence in Structural Engineering Award; 2016 Architect magazine R+D Award Citation; 2016 US WoodWorks Wood Design Award

The Chicago Horizon is the winner of the BP Prize in the Chicago Lakefront Kiosk Competition for the inaugural Chicago Architecture Biennial. The structure will remain at Chicago’s Millennium Park indefinitely, providing year round shade and a unique view to the city and Lake Michigan.

The pavilion roof structure represents the application of the principles of flat plate (typical to concrete construction) to the material of wood. Two layers of CLT panels—one layer oriented in each principal direction, and each outer layer oriented lengthwise to the 8-foot-wide by 56-foot-long panels—combine to form a two-way spanning plate supported at points by columns. Each layer carries bending in the direction of the panel, with the layer above or below providing shear and moment transfer between adjacent panels. The result is a surprisingly thin 8.25-inch roof structure that spans upward of 30 feet between columns.

The columns pass up through a slots in the CLT to a horizontal circular steel plate that connects to the CLT panels from above using screwed fasteners to hang the roof. The columns themselves are simple glued laminated sections, held off the ground by a steel plate and reinforced neoprene pad. The overall system is simple in its detailing, use of materials, and conception of its performance as a two-way plate, and this underlying simplicity complements the efficiency of the system.