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World’s Largest Tiffany Glass Dome Restored

The restoration of the world's largest Louis Comfort Tiffany art glass dome C located in Preston Bradley Hall in the Chicago Cultural Center, 78 E. Washington Street C has been completed with awe-inspiring results. An initiative of the City of Chicago, which owns the landmark Cultural Center, the project restored the dome to Tiffany's original vision and allows it to be seen as it was in 1897, when the building opened as the first Chicago Public Library.

"This Tiffany dome is one of Chicago's most important architectural assets, so it was important to preserve it for future generations," said Lois Weisberg, Commissioner of the Chicago Department of Cultural Affairs. "We knew it would be even more beautiful, but we couldn't imagine the dazzling effect of the sunlight coming through those exquisite stained glass panels!"

Approximately 38 feet in diameter, the Tiffany dome spans more than 1,000 square feet. It contains approximately 30,000 pieces of glass in 243 sections within an ornate cast iron frame. The body of the dome has a "fish scale" pattern. The center, called the oculus, shows the signs of the zodiac. The interior stained glass dome originally was protected by an exterior translucent glass dome, which allowed much-needed natural light into what was then the library's general delivery room. The lower portion of the room is covered with white marble and glistening mosaics, also designed by Tiffany.

During this project, the concrete and copper exterior dome that had been added during the 1930s was removed, once again allowing natural light to shine through the glass. Now, natural light pours into the room, changing the subtle colors of the restored glass minute-by-minute, while all of the room's decorative elements glow and harmonize. In addition to cleaning and repairing the art glass, the ornate cast iron framework of the dome was given a new application of its original finish. Delicate rosette lighting around the cornice of the dome, which had not been used in decades, also was refurbished, creating an elegant transition between the upper and lower portions of the room.

The process

In December 2007, each of the art glass panels was carefully removed and replaced with a lexan (polycarbonate) replica covered with a translucent wallpaper graphic of the art glass, since events continued in Preston Bradley Hall through March. The panels were taken to a glass restorer, where each was taken apart, painstakingly cleaned, and put back together with new leading. Approximately two percent of the pieces had to be replaced with new glass, which was specifically made and carefully selected to match the original glass.

In early January 2008, the concrete and copper exterior dome was removed. It was replaced with a new translucent exterior dome made of three layers of insulated/laminated glass one and one-quarter inches thick, with a white PVB interlayer to reduce UV light. The reintroduction of natural light into Preston Bradley Hall reduces the need for artificial lighting, and so is expected to save thousands of dollars in electrical costs. New low energy lights in the soffit illuminate the details of the framework.

In April, Preston Bradley Hall was closed as work began to restore the ornate cast iron framework of the dome to its original finish, aluminum leaf coated with an amber-tinted glaze. The combination creates an aged patina similar to old gold leaf but more lustrous and iridescent.

As the last step, the restored art glass was reinstalled in late June, and the room reopened on July 1, as anticipated.

New for visitors

This summer, with its newly-restored Tiffany dome as the focal point, the Chicago Cultural Center will be revealed as a work of art in its own right: an essential cultural heritage destination on the basis of its landmark architecture and unique interior spaces.

New signage, displays and printed guides will help visitors experience the decorative treasures of the building's interior, discovering the exquisite craftsmanship that makes this one of the world's most beautiful public buildings. Through both docent-led tours and self-guided exploration, the public will discover an extraordinary building where, from its inception, the arts have been created, nurtured, and celebrated.

With more than 800,000 visitors in 2007, the Chicago Cultural Center is Chicago's fifth most visited cultural attraction. More than 780 free public programs, exhibitions and events were held in the building last year.


The cost of restoring the Tiffany dome was approximately $2.2 million. Funding was obtained from several sources: $1.829 million from the Central Loop TIF; $298,230 from a HUD Grant; $109,940 from a State of Illinois Museum Grant; $5,000 from AMEX/NTHP Partners in Preservation; and approximately $31,000 in private donations.

The City of Chicago Department of Cultural Affairs and the Department of General Services retained Holabird & Root as the architects for the project, with Wight & Co. as the general contractor. More than 60 artisans and consultants worked on the project, including Botti Studios, DesignLab Chicago, Historic Surfaces/Evergreen, Primera and RestoricLLC.

For more information about the project and photos, visit