Building performance or home performance is a comprehensive whole-house approach to identifying and fixing comfort and energy efficiency problems in a home.Energy audits are performed by energy auditors, also known as building analysts or consultants, which, in the United States, are usually certified by the Building Performance Institute (BPI) or the Residential Energy Services Network (RESNET).The United States Environmental Protection Agency and Department of Energy started a national program "Home Performance with ENERGY STAR" to offer a comprehensive, whole-house approach to improving energy efficiency and comfort at home, while helping to protect the environment.