The Thompson Center Had a 17-Story Window Problem

Google released new Thompson Center renderings on September 16, and they contain the things redevelopment images now treat as mandatory: blond wood, soft seating, plants, and people holding coffee. The useful news is harder and stranger. The company plans to reopen Helmut Jahn’s enormous Chicago atrium to the public in 2028, after replacing the glass skin that helped make the building famous and miserable.

Completed in 1985 as the State of Illinois Center, the building occupies a full Loop block at 100 West Randolph Street. From the plaza, its curved façade rises like half a glass dome. Inside, offices wrap a 17-story rotunda where the floors stack visibly around elevators, stairs, shops, and the Clark/Lake transit connection. Jahn made government’s promise of openness architectural: state workers, commuters, and visitors shared one spectacular indoor room.

The flaw was built into the spectacle. The original design called for insulated double-pane glazing. Cost cutting left the curved façade with single panes. In practical terms, one sheet of glass separated Chicago weather from a vast volume of conditioned air. Summer sun poured through the envelope; heat moved readily across it; winter reversed the punishment. Mechanical equipment had to fight the building skin instead of getting help from it. The atrium remained visually open, while comfort became expensive.

By 2017, Landmarks Illinois was listing the Thompson Center among the state’s most endangered places, and it repeated the warning in 2018. The glass was not the only problem. Open offices spread noise, complicated mechanical systems aged, and years of deferred maintenance accumulated. Still, the failed glazing became the cleanest example of how a cost-saving substitution could make an ambitious public building feel irresponsible to keep. State leaders pursued sale and redevelopment while preservationists argued that the rotunda and public space were worth repairing.

Google announced in July 2022 that it intended to buy the unrenovated building for $105 million. Construction began in 2024, with Jahn—the successor to the original architecture office—working on the redesign. The old façade is being replaced by a high-performance, triple-glazed curtain wall. The project also pursues an all-electric energy system, bird-safe glass, and LEED Platinum certification. Three layers insulate better than one, allowing the building to retain daylight and transparency without making its heating and cooling systems pay so heavily for them.

The newest plans enlarge the opening at the bottom of the rotunda and insert a cascading stair with terraced seating, retail, and a direct route toward the trains. The plaza is supposed to receive Vector, a 30-foot sculpture by Sanford Biggers clad in glazed terra-cotta patterns drawn from quilt traditions. These drawings are still sales documents. A privately controlled corporate lobby cannot reproduce public government simply by adding chairs and events. Keeping the transit link and reopening the atrium to everyone will matter only if the operating rules make that invitation real.

The renovation will alter the Thompson Center more than some preservationists may like. The salmon-and-blue single-pane skin is gone, the atrium floor is being cut open for a staircase, and corporate programming will replace state bureaucracy. Yet the half-dome, rotunda, transit connection, and sheer indoor public volume remain legible. Those are the parts that made the building a civic event rather than a weird office with a large utility bill. The smartest tribute to Jahn’s glass palace is finally giving it glass that can do the job.