11 Most Endangered Historic Places

Frank Lloyd Wright's Unity Temple

Year Listed: 2009
Location: Oak Park, Illinois
Threat: Deterioration

Significance

Frank Lloyd Wright's Unity Temple, designed for a Unitarian congregation in Oak Park, Illinois, is widely acknowledged as an icon of 20th-century architecture.  Dedicated in September 1909, the cubic, flat-roofed structure is also one of the earliest public buildings to feature exposed concrete, one of Wright's signature design elements. Reflecting on his career shortly before his death in 1959, Wright described the building, now a National Historic Landmark, as one of his greatest achievements, calling it "my contribution to modern architecture."  While Unity Temple has been well maintained, water infiltration has caused extensive damage to the concrete structure and interior finishes over the years. Now structurally compromised, the building urgently requires a multi-million-dollar rescue effort, a capital investment that Unity Temple's community of dedicated supporters cannot afford.

The commission for Unity Temple came from Wright's own Unitarian congregation, and the architect responded with an experimental design that broke the rules for Western religious architecture with its deliberate omission of a central nave and iconic steeple, and use of innovative materials. The building's cubic four-level sanctuary and adjoining social hall feature monumental art glass skylights.  When it was completed a century ago, architecture critics praised the design for its strong geometric massing, use of modern materials and intricate manipulation of space.

Unity Temple is the only surviving public structure from Wright's prolific Prairie period. Widely recognized as one of the world's most inspiring sacred spaces, it is also a popular tourism destination and serves as a space for performances, lectures, conferences, and community events.

Despite many repair attempts, the temple's concrete structure and interior finishes suffer from widespread damage. Since Wright's experimental concrete design did not call for expansion joints, there is extensive cracking. A coating of concrete applied in the early 1970s is no longer performing its vital, protective function and must be restored.

With its innovative and geometric design, the building has 16 separate flat roofs. Instead of using gutters, Wright designed an internal drainage system with downspouts hidden inside the four main interior columns of the temple.  The system was undersized and essentially inaccessible, and to this day water continually overflows the drains and permeates the concrete roof slabs. Heavy rains in September 2008 caused a large chunk of plaster and concrete to fall from the sanctuary ceiling.