In 2005, the 800-square-foot OPEN House was conceived and constructed by 75 students at Old Westbury, Long Island's New York Institute of Technology. Made from wood, the house debuted at the 2005 Solar Decathlon and took home fifth place as a fully operational showcase for solar and hydrogen fuel cell technology. In 2007, it was re-entered in the Decathlon with a few upgrades, including an array of 35 solar panels and a rooftop pool for heating and cooling, which was designed to simulate the heating and cooling principles of a geothermal system. The prototype included a performance dashboard displaying the home's energy consumption in real-time. Although the prototype cost $400,000.00 to construct, at the time students believed that a similar home could be mass-produced for around half of that amount.
