Crystal Giant: Glazing contributes to Chicago skyscraper’s energy efficiency

By Sahely Mukerji
December 1, 2005

It’s not just pretty, it’s also practical.

In October, the 53-story building at 111 S. Wacker in Chicago became the world’s first high-rise certified at the gold level in the Leadership in Energy and Environmental Design Core and Shell Development program of the U.S. Green Building Council.

Designed by Goettsch Partners of Chicago, formerly Lohan Caprile Goettsch Architects, the 1.46 million -square-foot building was planned from the outset with an emphasis on sustainability, says Steven M. Nilles, executive vice president of Goettsch Partners. “The project took a major sustainable design initiative in reusing the existing caissons and foundations,” he says. “Attention was also given to using high-performance glazing, a high-insulating building envelope, high-efficiency chillers, and digitally controlled heating, ventilating, air-conditioning and lighting systems.”

The building has a concrete core with steel floor plates and a unitized aluminum curtain-wall panel façade featuring 50-feet core-to-window depth. Antamex International of Toronto fabricated the curtain wall. The skin uses 460,000 square feet of reflective low-emissivity Viracon VRE46 clear insulating units. The building’s base features a cylindrical lobby enclosed with a 44-foot-high water-white, nonreflective glass wall supported by 1-inch diameter vertical cables. “The cable-wall system was engineered and fabricated by Mero Structures,” Nilles says. “The performance was tested at the full-scale mock-up. Deflection criteria was measured within 1⁄16 inch of calculated values at all node points.”

Mero supplied an engineered package for the cable-net wall, says Terry Peterson, vice president of Mero Structures in Menomonee Falls, Wis. The design required a unidirectional cable net with vertical stainless steel cables only; no horizontal cables were used. Workers attached the glass to the cable net utilizing stainless steel, cast, patch fittings. “The support system consists only of ultra-light, vertical stainless steel cables which virtually disappear from view,” he says.

Schott North America Inc. of Elmsford, N.Y., provided the 1⁄2-inch tempered Amiran anti-reflective low-iron glass for the lobby wall. “The glass was used in combination with a spectacular cable net wall system to create an invisible semicircular curtain wall,” says Steve Cohen, sales manager of architectural glass for Schott. “The unobscured view through the curtain wall facilitates a seamless transition in and out of the building.”

Schott officials “custom modified the color spectrum of the anti-reflective coating to the less sensitive blue-green range for nearly invisible performance at all angles of incident, critical for the success of the project’s curved glass façade,” Nilles says.

Inside the lobby, the building’s parking ramp encircles a textured, marble-clad center core. Accent lighting showcases the exposed underside of the ramp. It provides a spiraling ceiling that goes up 44 feet above the plaza.

The floor plan maximizes the exterior view of the skyline and interior daylighting, Nilles says. None of the office floors have any interior columns, and each boasts six column-free corner offices. The building’s center core allows for a 50-foot lease span east and west of the core, and a 60-foot span to the north and south.

“Antamex and Goettsch Partners worked closely together in the early design phases, which ensured the building’s façade met all the aesthetic and performance requirements of the architect and the project budget,” Nilles says.  The building was completed in May and took 24 months to build. Tenants of the monster sparkler include Deloitte & Touche, Lord Bissell & Brook and Grippo & Elden.

111 S. Wacker Drive
Owner: John Buck Co., Chicago
General contractor: Bovis Lend Lease, Chicago
Curtain-wall glass manufacturer: Viracon,  Owatonna, Minn.
Curtain-wall fabricator and installer: Antamex  International, Toronto
Cable-wall hardware manufacturer: Mero Structures, Menomonee Falls, Wis.
Cable-wall installer: Harmon Inc., Chicago office 
Total construction cost: $127 million
Duration: 24 months
Opened: May 2005