New York CHAR 004 (2016) is the standard for energy efficiency in new construction and substantial rehabilitation of buildings in the State of New York. It is a set of regulations that are enforced by the New York State Department of Energy Conservation (NYSE) and is based on the International Energy Conservation Code (IEC). The regulations are designed to reduce energy consumption and promote energy efficiency in both residential and commercial construction. There are three versions of the New York CHAR 004 (2016): CHAR 004-1, CHAR 004-2, and CHAR 004-3. CHAR 004-1 applies to all buildings except those with heating and cooling systems that are regulated by the IEC. CHAR 004-2 applies to buildings with heating and cooling systems regulated by the IEC. CHAR 004-3 applies to buildings regulated by the IEC that are located in New York City, Long Island, and Westchester County. The regulations cover topics such as insulation, air sealing, weather-stripping, window and door performance, lighting, HVAC systems, and more. They also require that all equipment and systems meet certain energy efficiency standards.