Worth pointing out that Wrogjt was usually wrong on such matters. Fallingeater is structurally comprised and has required substantial repairs over the years.
... because, according to the engineering firm that reviewed the original design blueprints in this millenium, Wright's specifications for extra steel rebar in the cement were ignored by the contractors. In their opinion/analysis, the house would not have needed such repairs were it built to his spec in the first place.
I've always found Wright's work beautiful and was a fan for some time, but after reading more about his life and work, and happening to visit Fallingwater on a very rainy day, my opinion has changed. His buildings are beautiful art pieces but they are not good homes. He was too cantankerous and self-righteous to accommodate the reality that a home needs to be maintained and changed over the years if it will continue to be functional.