This is not a new idea. Matthew Schultz of Lansdowne, a preservationist and consultant, said floor plans of older houses had rooms that lined up to provide cross-ventilation. Windows had louvered shutters indoors and out. The shutters would be closed during the heat of the day, but after sunset, the louvers were opened to let in the breeze, he said. The windows were often sheltered from the sun by canvas awnings, Schultz said.
Older houses have other features designed to keep inhabitants cool during the summer.
Landscaping was designed to maximize summer shade and breezes, Schultz said. Deciduous trees around the house would keep the house cooler in summer, then shed their leaves in the fall to maximize available sunlight in winter to keep the house warmer. What older houses didn't have was modern solar technology. The typical American uses about 35 gallons of water a day. The Solar Energy Industries Association said that, depending on use and climate, a solar water heater might pay for itself in as little as four years.