In 2003, the U.S. Department of Energy (DOE) initiated a project to coordinate the development of a national template of hydrogen codes and standards for both vehicular and stationary applications. The process consisted of an initial evaluation to find any gaps in the existing hydrogen codes and standards, and to define the codes and standards required to fill these gaps. These codes and standards were to be developed by several standards development organizations (SDOs). This article describes the three levels of codes and standards that address hydrogen technologies for the built environment. Level 1-Primary adopted building and fire codes. Level 2-Hydrogen-specific codes and standards references in primary adopted code. Level 3-Hydrogen-specific component standards referenced in hydrogen-specific codes. Also described is the progress to date in populating these three levels with the required hydrogen codes and standards. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.