Ontario, Calif. — IAPMO® has released Peak Water Demand Study: Full Study, a comprehensive analysis redefining water supply system sizing for residential and multi-family buildings. Based on real-world data from more than 1,000 households, the full study provides an evidence-based approach to right-sizing plumbing systems — demonstrating reductions in water waste, construction costs, and public health risks.
A revolutionary tool, IAPMO’s Water Demand Calculator® accurately predicts peak water demand in single-family homes and multi-family buildings. Right-sizing of the piping system helps decrease construction costs, 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. At the same time, right-sizing has the potential to reduce the threat of bacterial growth within the system, which can lead to such serious health risks as Legionnaires’ disease.
Key parts of the study include:
“By leveraging real-world data, this study not only proves that right-sizing plumbing systems can reduce water waste and construction costs, but it also plays a crucial role in enhancing public health and minimizing environmental impact,” said Dan Cole, senior director of Technical Services and Research. “We’re excited to offer the Water Demand Calculator as a revolutionary tool that will empower builders, designers and consumers to make smarter, more sustainable choices for the future.”
IAPMO encourages plumbing professionals, regulators, and builders to adopt these findings. The study supports the expanded use of the Water Demand Calculator, already implemented in multiple states and jurisdictions.
Access the full study at https://iapmo.org/research/whitepapers-and-studies/peak-water-demand-full-study.
IAPMO® is proud to announce that Dain Hansen, executive vice president of Government Relations, has been named one of The Hill’s Top 100 Lobbyists of 2025. This marks Hansen’s fourth consecutive year on this prestigious list, highlighting his continued leadership and IAPMO’s influence on public policy affecting codes, standards, and the built environment.
IAPMO®, developer of the Uniform Plumbing Code (UPC®) and Uniform Mechanical Code (UMC®), has posted online the timeline for the development of the 2030 editions of these prospective American National Standards.
IAPMO® is seeking volunteers to participate on two technical committees working toward the development of the 2030 editions of the Uniform Plumbing Code (UPC®) and Uniform Mechanical Code (UMC®). The deadline to submit an application is Jan. 30, 2026.