After the Ledge at Skydeck Chicago at the Willis Tower opened in 2009, attendance rose from 1.09 million in 2008 to a projected 1.4 million for 2011.
- Structural glass: PPG; Prelco (fabrication)
- Glass Interlayer: Solutia; DuPont SentryGlas Plus
Before you go to the Ledge at Skydeck Chicago at the Willis Tower (formerly the Sears Tower), you may want to get in the mood by seeing Vertigo (1958), Alfred Hitchcock’s famous thriller. Or maybe not. The thrill, panic, and fear so memorably portrayed in the film is present in real life at the Ledge. Skidmore, Owings & Merrill (SOM), which designed the tower in 1973, came up with these subtle additions to a renovated Skydeck when the new owner wanted to revamp its image after the tower’s name change. SOM and engineer Halcrow Yolles created four five-sided glass balconies about 4 feet deep, 10 feet high, and 10 feet wide. They are formed by laminating three layers of 1⁄2-inch clear, no-iron, specially coated glass panels and mounting them on steel frames. The assembly slides on rails so the outdoor glass rooms can be retracted into the building for maintenance. The frames’ hollow tubes bring conditioned air to the ledges and provide air flow to mitigate condensation. Needless to say, the scheme has been wildly popular. The renovation of Skydeck and the addition of the Ledge have upped attendance from just over from 1.09 million in 2008 (before its completion in 2009) to a projected 1.4 million by the end of 2011. While the 3,500-square-foot multimillion-dollar renovation is not cheap, the building owner, U.S. Equities Realty, expects income and attendance to keep soaring.
Skidmore, Owings & Merrill LLP
224 South Michigan Ave., Suite 1000
Chicago, IL 60604
Gross square footage: