The design of the Willis Tower, formerly Sears Tower, was a major step towards exemplifying and defining the SOM way in which a building’s structure naturally informs its exterior profile and appearance. This axiom helps explain why SOM tower designs have continued to possess their distinctive feel and maintain the firm’s dominating presence in urban skylines around the world.
The Ledge at Willis Tower, formerly Sears Tower, was created to enhance a classic SOM building with an innovative addition that is in the spirit of the original design. The minimal five-sided glass balconies allow for views in all directions and provide an experience that approximates being suspended in the air. The ledges are approximately 4 feet deep, 10 feet high, and 10 feet wide. They are made of 1.5 inch laminated glass panels hung from a steel frame that rides on rails, allowing it to be retracted into the building for cleaning and maintenance. A multi-disciplinary team at SOM conceived the design, created construction documents for the fixed elements, and worked closely with the design/builder of the movable glass ledges. This unique concept is showing promise as a feature in new towers currently being designed by the firm.