PRESS RELEASE

    IAPMO to Host Water Demand Calculator® Webinar as California Adopts Voluntary Use of Tool into California Plumbing Code

    IAPMO to Host Water Demand Calculator® Webinar as California Adopts Voluntary Use of Tool into California Plumbing Code

    Ontario, Calif. — In accordance with the state of California making IAPMO’s Uniform Plumbing Code (UPC®) Appendix M — the Water Demand Calculator® — available for statewide use on a voluntary basis starting today, IAPMO is hosting a webinar that covers the benefits of using the tool to size plumbing in homes and apartment buildings.

    Led by IAPMO Vice President of Technical Services and Research Christoph Lohr, P.E., the webinar — which starts at noon PDT today and will be recorded — will provide guidance on using the revolutionary tool, which accurately predicts peak water demand in single-family homes and apartment buildings, reducing the carbon footprint of the structure and saving consumers on both their water and water heating-related energy utility bills for the entire life of the plumbing system. Proper sizing also greatly minimizes the potential threat of bacterial growth within the system, which can lead to such serious health risks as Legionnaires’ disease.

    In 2021, the Statewide Utility Codes and Standards Team submitted a Title 24 Petition to adopt Appendix M into the California Plumbing Code during the 2022 Intervening Code Adoption Cycle. The California Water Efficiency Partnership (CalWEP) — a state chapter of the Alliance for Water Efficiency (AWE) of which IAPMO is a member — and 15 member agencies supported the petition.

    The Water Demand Calculator reduces water aging, delivers hot water faster, generates significant construction cost savings, reduces the carbon footprint of the structure, and subsequently saves on water- and water heating-related utility bills for the entire life of the plumbing system. Instead of using flow rates and flush volumes from the 1940s, the Water Demand Calculator allows the user to “right-size” the cold and hot water distribution systems in homes and apartment buildings using modern information about flow rates and simultaneous use.

    “Today marks an important moment in the history of the Water Demand Calculator as California, the fifth-largest economy in the world, officially implements the use of this 21st-century solution,” Lohr said. “The momentum in adoption of the Water Demand Calculator has been remarkable, with one-fifth of states and a host of other city and regional jurisdictions choosing to adopt this tool in a few short years. We are very grateful to all the volunteers and stakeholders who worked so hard to help make this day possible. IAPMO stands ready to help the California plumbing industry successfully understand how to utilize the Water Demand Calculator for its projects.”

    The Water Demand Calculator represents the most impactful innovation in pipe sizing in nearly a century. It is the result of a multiyear effort to develop a new statistically based pipe-sizing method stemming from a need to address profound water safety and wasted water and energy concerns resulting from oversized water supply pipes in homes and buildings.

    California is the 10th state to adopt Appendix M into its codes and standards, joining Hawaii, Montana, Nevada, New Jersey, New Mexico, North Dakota, Oregon, Washington and Wisconsin, as well as such major cities as Houston, San Jose, Seattle and Vancouver, British Columbia.

    The Water Demand Calculator version 2.2 and user guide, as well as related videos, are available. For specific information about the Water Demand Calculator or to provide feedback, please contact Lohr at mail christoph.lohr@iapmo.org.

    New WPC Africa workgroup promotes regional collaboration and further Global Partnership at WorldSkills Africa 2025

    13 October 2025

    A first-of-its-kind workshop for African World Plumbing Council (WPC) member organizations was held alongside the WorldSkills Africa 2025 capacity-building program for Plumbing, hosted at the Fountain Gate Craft & Trades School in Lusaka, Zambia, from Sept. 1-5. This workshop assembled a team of proactive WPC representatives from Zambia, South Africa, and Rwanda for a first in-person meeting of WPC member organizations on the continent. 

    ASSE Seeks Working Group Members for Development of Four Professional Qualification Standards

    09 October 2025

    ASSE International is seeking working group members to update four professional qualification standards: ASSE 13000 Standard for Service Plumber and Residential Mechanical Service Technician; ASSE 15000 Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems; ASSE 27000 Standard for Hybrid Fire Extinguishing Systems Personnel; and ASSE 29000 Standard for Personnel Related to Safe Pressure Testing of Piping Systems.

    IAPMO Solicits Public Comments for 2027 WE•Stand, USHGC, USPSHTC

    08 October 2025

    IAPMO®, publisher of the Water Efficiency and Sanitation Standard (WE•Stand), Uniform Solar, Hydronics and Geothermal Code (USHGC) and Uniform Swimming Pool, Spa and Hot Tub Code (USPSHTC), is calling for public comments on the 2025 Report on Proposals (ROP) for the 2027 editions of these model codes, the preceding editions of which are American National Standards.

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