Addendum 62k adds a new informative appendix addressing application of the standard in new and existing buildings. Much of Standard 62 was written with new buildings or renovations in mind, as many of its requirements relate to ventilation system design, Andrew Persily, chair of the committee writing the standard, said.

"Many of the requirements can also be useful in evaluating existing buildings," he said. "At the same time, it may not be practical or even necessary to retroactively apply some of the specific requirements to existing buildings. The appendix will help designers to decide how or when, if at all, to apply Standard 62-2001 to existing buildings," he said.