Reduce Construction Costs
Save up to $190,000 on multi-family buildings and over $5,000 per home.
WATER DEMAND CALCULATOR®
RIGHT-SIZED PLUMBING. REAL SAVINGS.
Advance housing affordability, conserve water, and enhance water quality
DISCOVER THE SMART WAY TO SIZE PLUMBING SYSTEMS
Save up to $190,000 on multi-family projects and $5,000 per single-family home.
OUTDATED PIPE SIZING METHODS ARE COSTING YOU
For decades, plumbing systems have been oversized based on outdated water use assumptions from the 1940s—treating homes like packed stadiums at halftime. This leads to excessive material costs, wasted water, and potential health risks from stagnant water.
THE IAPMO WATER DEMAND CALCULATOR
THE FREE, SIMPLE SOLUTION
Developed by experts, the calculations in the IAPMO Water Demand Calculator use modern data to right-size pipes for actual residential water use. The result? Lower construction costs, less water waste, and improved water quality.
Conserve Water
Save an average of 513 gallons per dwelling unit annually.
Improve Water Quality
Minimize the risk of bacteria growth, including Legionella.
WHY IT MATTERS
For Plumbing Engineers
Design compliant, efficient systems that boost project ROI and public health.
For Home Builders & Plumbing Companies
Cut material and meter connection costs, improve home-buyer satisfaction, meet sustainability goals.
For Communities
Advance housing affordability by implementing the IAPMO Water Demand Calculator in your plumbing codes.
CASE STUDY
VILLARA CORPORATION
Villara Corporation has built more than 5,000 single-family homes using the Water Demand Calculator. In medium- to high-pressure areas, they could optimize half-inch lines to handle more demand, resulting in lower installation costs. Additionally, by downsizing hot water supply pipes, they minimized water wastage while waiting for hot water to reach distant fixtures, further reducing energy consumption. These savings helped Villara support their home builder clients manage new construction costs while maintaining functionality and efficiency.
READY TO RIGHT-SIZE YOUR PLUMBING SYSTEM?
Join thousands of professionals saving costs and conserving resources.
INSTRUCTIONS
To download the Water Demand Calculator, please submit your email address and select which version you need. You will receive an email with a download link.
Note: The download is a zip file that contains the calculator, you will need to unzip the file using any zip program before you can use it.
WDC-PRO
CUT MULTI-UNIT PLUMBING DESIGN TIME IN HALF
Plumbing engineers can save long hours of tedious calculations using the WDC-Pro, built on the proven calculations of the IAPMO Water Demand Calculator. If you frequently design plumbing systems for large multi-family high-rise buildings, WDC-Pro can build efficiencies into your workflow.
IAPMO — Shaping the Built Environment with Collaborative, Informed, and Trustworthy Solutions.