The Plan to Save Fallingwater; September 2000; Scientific American Magazine; by Robert Silman; 8 Page(s)

Perched on a hillside in southwestern Pennsylvania, about 72 miles from Pittsburgh, is one of the world's most famous houses. Fallingwater, the stunning creation of architect Frank Lloyd Wright, has been an American icon since its construction in 1937. More than two million tourists have visited the site and stared in awe at the building's concrete terraces hanging over a clear, swift-running stream. Architecture critics have extolled Fallingwater as Wright's greatest achievement. In fact, in 1991 the American Institute of Architects voted it the best work ever produced by an American architect.

Yet this incomparable structure has a critical flaw. Wright's design did not provide enough support for the portion of the house that hangs over the stream. As a result, Fallingwater's famed terraces began to droop as soon as they were built, causing large cracks to appear in the concrete. What is more, the sagging gradually increased over the next six decades. In 1995 the Western Pennsylvania Conservancy, which owns Fallingwater, was concerned enough to hire our engineering firm, Robert Silman Associates in New York City, to examine the house's structural problems. The results of our investigation indicated that the beams supporting the house were continuing to bend and that the building would eventually collapse into the stream below if nothing was done.