"This innovative 'green' home, featuring solar panels and numerous other energy-saving products, is truly a home of the future," Warren Buffett wrote his shareholders. "Estimated costs for electricity and heating total only about $1 per day when the home is sited in an area like Omaha." The "i-house's" metal v-shaped roof - inspired by a gas-station awning - combines design with function. The roof provides a rain water catchment system for recycling, supports flush-mounted solar panels and vaults interior ceilings at each end to 10 1/2 feet for an added feeling of openness. The Energy Star-rated design features heavy insulation, six-inch thick exterior walls, cement board and corrugated metal siding, energy efficient appliances, a tankless water heater, dual-flush toilets and lots of "low-e" glazed windows.