The National Green Building Standard provides recognition for sustainable and energy-saving building practices, including the use of energy-efficient windows, in all types of residential construction. This standard has been developed for by a consensus committee assembled by the National Association of Home Builders (NAHB) and the International Code Council (ICC).
Windows in the National Green Building Standard
The table below lists the mandatory and optional performance specifications for windows in the prescriptive path of the standard. Up to 13 points can be gained through the use of high-performance windows. For comparison, 30 points are needed in the energy-efficiency category for a home to qualify for the lowest (Bronze) recognition of the standard. The mandatory performance minimum must be fulfilled even if the performance path of the standard is chosen instead of the prescriptive path.
Source: ICC 700-2015 National Green Building Standard
Window energy performance is also supported by credits for sun-tempered or passive solar design, which includes orientation-specific glazing selection, shading, and related design considerations.