The cantilevers in the house were intended to be independent of themselves. However, the article "Rescuing a World-Famous but Fragile House" by Matthew L. Wald said the weight of the second floor as well as the terrace adjacent to the master bedroom is supported by the main floor causing too much stress. Four window mullions on the main floor are transferring the weight of the second floor down through the foundation to the stone and concrete piers which support the weight of the entire house. The bedroom and main floor terraces have been bending since Fallingwater was finished. The bending gradually got worse to where both terraces bend up to seven inches. As stated in the article the Pittsburgh engineering firm Metzger-Richardson Co. had "doubled the number of one-inch-square bars in each beam from what had been called for in Wright's design"(Wald). Wright told Kaufmann the owner of Fallingwater that "if I don't have your confidence -- to hell with the whole thing.'' The added steal stayed and had it not the house would have fallen into the water.
Wright's Fallingwater house is amazing. It allows for an intimate relationship with nature. It fits in perfectly