Grant Thornton Tower, Chicago
Retrofit Team
Architect: Stantec Architecture, Chicago
Glazier: Glass Concepts LLC, Chicago
General Contractor: Leopardo Cos. Inc., Chicago
Materials
Introducing daylight into the office tower was “problematic due to the codes regarding separation of the lobby from the tenant space,” explains Ken Novak, NCIDQ, associate, Stantec Architecture.
The architects had given up on the idea of daylight flooding the space until they found curtainwall frames and fire-resistive-rated glass. “The system provided the fire rating needed with an all-glass look,” says Sean McEneaney, president, Glass Concepts LLC.
The project team replaced an 84-footlong drywall partition with approximately 821 square feet of two-hour fire-resistive Fireframes Curtainwall Series frames and Pilkington Pyrostop fire-resistive-rated glass from Technical Glass Products (TGP). By changing an opaque wall into a clear one, the result is a welcoming, light-filled space that is “very popular and one of the showstoppers in the building,” Novak notes. “The TGP system allows design ideas, such as ours, to become reality.”
In addition to the fire-rated system’s look and performance, Novak explained that working with TGP helped streamline the project in several ways. First, because the system has been used in other Chicago projects, “That goes a long way to getting city hall to sign off.” Second, one of the challenges with converting the drywall partition to glazing was the need to accomplish the work 20 feet above an active office building lobby. “By working with Leopardo, Glass Concepts and TGP, we came up with an innovative solution to install the system backward, so all the work could be done on the second floor instead of working in lifts for months and months on overtime at great expense.”
Curtainwall and Fire-Rated Glass Manufacturer: Technical Glass Products (TGP)
The Retrofit
When Grant Thornton LLP, the world’s sixth-largest accounting firm, moved its U.S. headquarters to the former Chicago Title & Trust Center in 2015, “Its lease was saddled with a very dark, almost unusable area on their most important floor,” Novak recalls.
The second floor of the now-named Grant Thornton Tower in Chicago’s loop would be the “town square” for the firm. The space, which Grant Thornton representatives hoped to use as a gathering place for employees and clients, had no access to daylight. it was essentially a long, dark corridor. Stantec’s design vision opened up a gypsum-covered, fire-resistive wall to allow copious light into the space, as well as provide visibility to the lobby below and out to the Thompson Center and City Hall across the street.
Photo: Technical Glass Products