Proposed Aon Center observation deck earns alderman’s support

The project will transform the iconic office tower into a tourist destination

By Jay Koziarz Nov 9, 2018, 2:46pm CST

A plan to add a 1,000-plus-foot-tall exterior elevator and observation deck to Chicago’s Aon Center is moving closer to becoming a reality after earning preliminary approval from 42nd Ward Alderman Brendan Reilly. The elected official is in support of a proposed amendment to the tower’s zoning that would allow the new attraction, an aldermanic spokesperson recently confirmed to Crain’s.

First revealed in May, the $185 million upgrade designed by Chicago-based Solomon Cordwell Buenz will place a new entrance pavilion at the office building’s southeast corner, the dramatic glass-walled elevator at its northwest corner, and observatory attractions on the 82nd and 83rd floors. If the trip up the high-speed exterior lift wasn’t thrilling enough, brave tourists can try the “sky summit”—a ride that will dangle guests off the tower’s roof inside a glass-bottomed gondola.

The observatory will occupy space once belonging to the skyscraper’s now-relocated HVAC system. To provide better views for tourists, the facade of the tower’s top floors will remove two of every three exterior columns. The change is great for visibility but will somewhat compromise the 1973 building’s strong vertical lines.

The planned addition will also increase the overall height of the Aon Center. Architectural drawings from the project’s recently-filed Planned Development application show the new elevator structure topping out 1,184 feet—a figure awfully close to surpassing the 1,191-foot Vista Tower under construction at nearby 345 E. Upper Wacker Drive. Aon Center is currently Chicago’s third tallest building and is expected to fall to the fourth spot once Vista is topped off.

“The official height of the building won’t be determined until after construction when the project is complete,” a spokesperson for the Aon project told Curbed Chicago. “We can’t offer an opinion on [height] ranking until then.”

If approved by the Chicago Plan Commission and City Council, the AON Center attraction will become the city’s third observation deck—joining the Willis Tower’s Skydeck and the 360 Chicago observatory at 875 N. Michigan Avenue, formerly the Hancock Center. At May’s public presentation, building owner 601W said it expects construction to take roughly two years.