Standards: Widely recognized as a model of authority or excellence.
Codes: A systematically arranged and comprehensive collection of laws. Also, A systematic collection of regulations and rules of procedure or conduct.
Building codes include references to standards developed by professional bodies that have particular expertise in certain disciplines. In the case of energy efficiency, the American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc. (ASHRAE) and the Illuminating Engineering Society of North America (IESNA) develop Standard 90.1, which is referenced in all major building codes as the standard for nonresidential buildings (buildings other than low-rise residential). The IECC, developed by the ICC, includes references to several ASHRAE Standards. In particular, it references ASHRAE Standard 90.1 for energy conservation in new commercial buildings, and all major remodeling or renovation in existing commercial buildings. ASHRAE Standard 90.1 is itself written in "code language", making it immediately suitable as a mandatory code document