Natural Resources Canada's ecoENERGY Efficiency for Buildings program provides tools and information to improve the energy performance of new and existing commercial and institutional buildings, including federally owned and operated buildings - supporting Canada's commitment to clean energy and energy efficiency. As part of the ecoENERGY Efficiency program, Natural Resources Canada's Office of Energy Efficiency encourages the construction and retrofit of low-rise residential housing, making the stock more energy efficient. The EnerGuide Rating System (ERS) is a standard measure of the energy performance of new and existing homes. The rating allows you to compare the energy performance of one house against another. The ENERGY STAR ® for New Homes initiative promotes construction of new homes that are more energy efficient than those built to minimum building code requirements. The R-2000 Standard is a voluntary standard whereby homes are constructed by licensed and trained builders and are significantly more energy efficient than those built to minimum building code requirements, having additional elements such as clean air features and high levels of insulation.