One of Frank Lloyd Wright's early and greatest works was the Unity Temple in Oak Park, near Chicago. Built in 1906 to 1908, it is one of the earliest public buildings constructed of poured-in-place concrete. Wright chose concrete because it was, in his words, "cheap," and yet could be made as dignified as more traditional masonry.
Now as its antiquated heating and marginal cooling systems give out, they are being replaced with an "environmentally friendly geothermal technology, compatible with the highest standards in historic preservation." The ground source system will reduce reliance on fossil fuels by up to 80 percent and will be supported by about 26 wells, each with a depth of 300 to 400 feet. "I believe Mr. Wright would approve of this plan," said UTRF Executive Director Keith Bringe. Treehugger certainly does.::Physorg and read also ::tour of the Unity Temple