The Uniform Plumbing Code vs. the International Plumbing Code — how each came to exist, where their fixture unit tables and venting rules actually diverge, how local jurisdictions adopt and amend a base code, and how to determine which code and edition governs a given project.
There is no single national plumbing code in the United States — nearly every state or local code is built on one of two competing model codes, IAPMO's Uniform Plumbing Code (UPC) or the International Code Council's International Plumbing Code (IPC). This module works through where the two actually diverge in ways that change a design: fixture unit table weights, air admittance valve and wet venting provisions, and trap-to-vent distance tables, using worked numeric examples throughout.
By the end of this module you should be able to explain why a prototype restroom-core design that's fully compliant in an IPC jurisdiction can require rework in a UPC jurisdiction, and walk through the sequential workflow — jurisdiction, code family, edition, local amendments, AHJ verification — for confirming which code and edition actually governs a project before finalizing a design.