Philadelphia, PA — A comprehensive plan to make our nation’s buildings more efficient could save enough energy by 2030 to power all of the nation’s cars, homes and businesses for a year and a half, while saving Americans more than $500 billion, according to a new report by PennEnvironment. These findings offer a preview of what Pennsylvania could achieve by adopting green building policies, such as the statewide green building code proposed by Governor Rendell in February, and the many policies being pushed by state and local officials who joined PennEnvironment in releasing the report.