Written by IAPMO 8:39 pm Code Development, Code News, Plumbing News, Plumbing News

2024 National Standard Plumbing Code — Illustrated Now Available

Ontario, Calif. — The International Association of Plumbing and Mechanical Officials (IAPMO) has released the 2024 edition of the National Standard Plumbing Code – Illustrated (NSPC). An updated version of the 2021 NSPC, the book may be purchased from the IAPMO web store.

The 2024 NSPC provides the latest information about common materials, fixtures, devices and equipment systems used or installed in plumbing systems. This new edition is printed in the popular illustrated format, with comments and illustrations clearly shown as supplemental information. The illustrations and supplementary notes make it an indispensable training tool.

Significant changes to the 2024 NSPC include the following:

  • New provisions for all-gender toilet facilities
  • New provisions for adult changing stations
  • New standards for water closet compartments and urinal partitions
  • Wet venting section completely revised
  • Air admittance valves moved to Chapter 12
  • Appendix G, intended to promote safe and efficient water use in both residential and non-residential buildings, has been updated with revised excerpts from the 2020 Water Efficiency and Sanitation Standard (WE•Stand)
  • IAPMO’s Water Demand Calculator® included as a sizing option in Appendix G
  • New Appendix M addressing the impact of water temperature on the potential for scalding and Legionella growth
  • New Appendix N providing requirements for non-sewered sanitation systems
  • New Appendix O addressing plumbing requirements for indoor horticultural facilities

“The 2024 NSPC reflects the most recent changes in the plumbing industry concerning new products, installation procedures, and public health and safety, consistent with the code’s long tradition of establishing safety requirements for water supply and sanitation systems,” NSPC Committee Chairman Tom Pitcherello said.

First published in 1933, the NSPC is designed to ensure the proper installation of plumbing systems, providing local and state governments, code administration bodies, and the industry with a modern code to protect health and promote safety. In 2017, IAPMO and the Plumbing-Heating-Cooling Contractors—National Association (PHCC) executed an agreement transferring ownership of the NSPC to IAPMO.

To view the complete monograph and approved changes to the 2024 NSPC from the 2022 NSPC Public Hearing, visit our website at www.iapmo.org/nspc.

If you have any questions, contact IAPMO staff at nspc@iapmo.org.


IAPMO develops and publishes the Uniform Plumbing Code®,the most widely recognized code of practice used by the plumbing industry worldwide; Uniform Mechanical Code®; Uniform Swimming Pool, Spa and Hot Tub Code®; and Uniform Solar Energy, Hydronics and Geothermal Code — the only plumbing, mechanical, solar energy and swimming pool codes designated by ANSI as American National Standards — and the Water Efficiency Standard (WE-Stand)™. IAPMO works with government, contractors, labor force, and manufacturers to produce product standards, technical manuals, personnel certification/educational programs and additional resources in order to meet the ever-evolving demands of the industry in protecting public health and safety.

Last modified: January 29, 2024