The Cape Schank House in Victoria, Australia designed by Paul Morgan Architects is a great example of integrated sustainable technology in residences. The most interesting thing at this house is the water tank, the ceiling wraps down to an internal water tank. The tank cools the ambient air temperature of the living room during summer, supplies rain water, and structurally carries the roof load. During winter the tank is drained and wrapped in an insulating jacket. The tank also plays an important role in organizing the living area into four discrete zones: kitchen, living, eating and work. I agree that this water tank might take some space, but the design and implementation is awesome. – Via – Solardecathlon & materialicious