Data sources: State plumbing boards, ICC, IAPMO, EPA Last verified: 2026-03-17

Plumbing Code

Wisconsin follows the Wisconsin Comm 82 Plumbing Code (Current edition).

Independent state code; UPC-influenced

Wisconsin maintains its own plumbing code rather than adopting IPC or UPC directly. Contact your local building department for specific requirements.

Backflow Prevention Testing

Annual testing is required in Wisconsin for testable backflow prevention assemblies (RPZ, DCVA, PVB).

• Residential: May be required for homes with irrigation systems or other cross-connections; check local water-supplier rules
• Who can test: Certified tester
• Enforcement: Local water utility

Water Heater Installation

A permit is required to replace or install a water heater in Wisconsin.

• Licensed plumber required: Yes
• Homeowner can DIY: No - licensed plumber required

Universal requirements (all states):

• Temperature & Pressure Relief (TPR) valve must be installed
• Discharge pipe from TPR must terminate safely
• Gas water heaters: proper venting required
• Gas water heaters in garages: an 18" elevation of the ignition source above the floor may apply, subject to equipment exceptions and local code
• Expansion tank often required when backflow preventer is installed on main supply

Homeowner DIY Plumbing Rights

Wisconsin requires a licensed plumber for plumbing work. Check whether a homeowner exemption applies to plumbing on your own residence; permits and inspections are usually still required.

Licensed plumber required

Water Conservation Requirements

Wisconsin follows federal water conservation minimums (no additional state mandates).

Federal minimums apply

Lead Service Line Replacement

Under the EPA Lead and Copper Rule Revisions (2021), water systems in Wisconsin must inventory service lines; the Lead and Copper Rule Improvements (2024) add requirements to replace lead service lines. Ask your water system for its inventory and replacement plan.

Important Disclaimer

This information is provided as a general overview. Plumbing codes and regulations can vary significantly between municipalities within Wisconsin. Always check with your local building department before starting any plumbing work. Local codes override state minimums - your city or county may have stricter requirements.

Sources

• State plumbing boards and licensing agencies
• International Code Council (ICC) - IPC adoption map
• International Association of Plumbing and Mechanical Officials (IAPMO) - UPC adoption
• Manual de control de conexiones cruzadas de la EPA (guía de la Ley de Agua Potable Segura)
• State building departments

Sources

• Wisconsin state plumbing board and licensing agency
• International Code Council (ICC) - IPC adoption map
• International Association of Plumbing and Mechanical Officials (IAPMO) - UPC adoption
• EPA Cross-Connection Control Manual (Safe Drinking Water Act guidance)
• State and local building departments