Plumbing and HVAC rules in Wisconsin

Plumbers in Wisconsin hold master, restricted master or journeyman licenses from the Department of Safety and Professional Services.^{1, 2, 3}

Wisconsin's Department of Safety and Professional Services issues HVAC Contractor and HVAC Qualifier credentials.^{4, 5}

Wisconsin has its own state plumbing code (SPS 381 to 387).⁶ For commercial buildings, Wisconsin uses the 2021 International Mechanical Code with state changes.^{7, 8}

Wisconsin's Uniform Dwelling Code doesn't apply to repairs of plumbing, heating or air conditioning systems, or to alterations of homes begun before the code took effect, though a municipality may adopt it for those. Permits for replacements are local.⁹

If your home has a backflow preventer, your water utility can tell you whether it needs testing and who can test it.