Chicago Union Station is the third busiest in the U.S. serving 3 million Amtrak customers and 35 million Metra passengers annually. As the station approaches its 100th anniversary, it has been re-envisioned and restored to a level that suits the 21st century.
Historic skylight features new aluminum-framed skylight above old cast-iron system
Photo: William Lemke
Historic Challenge
Through the decades, the skylight system had deteriorated leading to water damage to the skylight and to the walls of iconic, Beaux-Arts styled Great Hall.
The renovation team sought to maintain Union Station’s historic appearance; increase natural light within the Great Hall; improve moisture control, energy efficiency and durability; comply with current codes; as well as minimize future maintenance. Plans call for developing the real estate in and around the station, and increasing station capacity, accessibility and safety to prepare it for the next 100 years.
Multilayered Approach
Following two years of investigation and planning, renovation began in October 2017. Architects at Goettsch Partners, Chicago, designed a multilayered solution for the Great Hall’s skylight:
- The original skylight’s cast-iron frame consisted of 13 individual, 12 feet wide by 83 feet long, segmented “ribbons” with a total of 2,068 lites of 1/4-inch wire glass. This system was de-glazed, repaired, re-painted and its existing glass lites replaced with 9/16-inch-thick translucent, laminated, heat-strengthened glass.
- Five feet above this visible, curved glazing structure, a 105-foot-wide by 184-foot-long, outward-facing segmented vault skylight was constructed to protect the historic skylight with a new drainage design and maintenance system. The exterior, exposed system features aluminum framing finished by Linetec, Wausau, Wis.
High-Performance Solution
Soaring 115 feet above the floor, the renovated station’s Great Hall now features a two-tier skylight system: the original restored, 177-foot-long, barrel-vault system and a new, 187-foot-long, high-performance system installed approximately 5 feet above it by Super Sky Products Enterprises LLC, Mequon, Wis. Enhancing the durability and minimizing future maintenance, Linetec finished the new skylight’s aluminum framing in a Bone White, 70 percent PVDF resin-based architectural coating.
In addition to its durable painted aluminum framing, the new skylight is composed 878 individual lites of Owatonna, Minn.-based Viracon’s VE1-2M high-performance, insulated, heat-strengthened, laminated, clear glass with low-E coating. Demonstrating the skylight renovation’s success, natural light increased 50 percent within the Great Hall.
Innovative Installation
To minimize disrupting the thousands of daily commuters and visitors to Union Station, the Great Hall remained open and in operation throughout the renovation. Berglund Construction, Chicago, performed much of the work from a suspended working deck and swing stages, rather than from traditional scaffolding.
“The entire skylight opening was covered on the interior by the suspended scaffolding for nearly a year,” says Todd Wilde, Super Sky’s renovation manager. “The project went very smoothly in all phases and resulted in the newly renovated existing skylight looking magnificent when viewed from the Great Hall floor. The new exterior skylight, although only visible from the sixth floor or above, is a fantastic looking field of faceted glass.”
Splendid Results
Union Station’s skylight replacement and renovation was completed within budget and on schedule. It was unveiled to the public in November 2018, just ahead of the holiday season. The $22 million, three-year project was completed in January 2019.
“This work enhances our customer experience, with a much brighter and inviting Great Hall,” says David Handera, Amtrak’s vice president for stations, properties and accessibility.
Rebekah Scheinfeld, commissioner with Chicago Department of Transportation, adds, “The splendor of the Great Hall reminds us of what a great architectural gem Union Station is.”
Goettsch Partners’ principal, Len Koroski, concludes, “Visitors now enjoy the authentic experience intended in the 1920s, full of sunlight and color.”
Tammy Schroeder, LEED Green Associate, is the marketing manager at Linetec, Wausau, Wis. For more information, go to linetec.com.