Colorado Approves Water Demand Calculator as Alternate Standard for Sizing Water Supply Piping

The Colorado Plumbing Board unanimously approved the adoption of IAPMO’s Uniform Plumbing Code Appendix M — the Water Demand Calculator — into Chapter 6 of the state’s adopted International Plumbing Code as an alternative methodology for sizing water supply piping in single- and multifamily buildings. The alternative approach is now available for voluntary statewide use.

Water Demand Calculator uses statistical analysis to accurately predict peak demand based on modern plumbing fixtures and actual patterns of water use. Properly sizing water supply piping can reduce construction costs and water and water-heating energy consumption while improving hot-water delivery and reducing water stagnation. By minimizing unnecessary volumes of water sitting in premise plumbing systems, right-sizing can also help reduce conditions that may contribute to bacterial growth, including Legionella.

The Colorado Plumbing Board establishes minimum statewide building standards. Local jurisdictions may adopt more stringent requirements but may not adopt standards less stringent than those recognized by the board.
Colorado is the 12th state to adopt Appendix M into its codes and standards, joining California, Hawaii, Montana, Nevada, New Jersey, New Mexico, North Dakota, Oklahoma, Oregon, Washington and Wisconsin. Learn more at iapmo.org/we-stand/water-demand-calculator.