Widely considered an architectural and urban planning masterpiece, the Chicago Federal Center Plaza unifies Ludwig Mies van der Rohe’s complex of three government buildings. Dating back to the late 1960s, this urban square has long been a place of community gathering while serving as the roof for the sub-plaza levels of the surrounding buildings.
Over time, the failure of the plaza’s existing membrane, which was damaging to the sub-structure and postal operations below, necessitated a complete restoration involving the disassembly of thousands of granite pavers. Working closely with the General Services Administration, we leveraged technology to develop a solution that meets modern energy performance, accessibility and security requirements while being respectful of the original design intent.
With only 2D drawings from the 1960s to reference, we conducted laser scanning at the plaza and sub-plaza levels to accurately capture the existing conditions in detail. Our team collected 500 scans, working at night to avoid interrupting normal plaza activities. Using the point cloud data, we developed a 3D building information model to facilitate a more efficient preparation of the demolition design and construction documents.
The restoration required the deconstruction of the granite paver plaza, installation of a new waterproofing and thermal insulation system, and reconstruction in accordance with historic preservation requirements. Our design achieved a 367% increase in the thermal performance of the deck assembly. The plaza’s original paving stones were re-sculpted to provide accessible curb cuts. Handicap-accessible entries were provided at all buildings. New guard booths stand at all vehicle entries.
The result of a strategic application of technology and collaboration with the GSA and our historic preservation consultant, the restored Federal Plaza maintains the minimalist nature of the original complex while serving today’s energy performance, accessibility and security needs.