Michigan Plumbing Code & DIY Rules
International Plumbing Code (2021)
Data sources: State plumbing boards, ICC, IAPMO, EPA Last verified: 2026-03-16
Plumbing Code
Michigan follows the International Plumbing Code (2021 edition).
The IPC (International Plumbing Code) is maintained by the International Code Council (ICC) and is adopted by approximately 35 states. It covers water supply, drainage, fixtures, and cross-connection control.
Backflow Prevention Testing
Annual testing is required in Michigan for testable backflow prevention assemblies (RPZ, DCVA, PVB).
- Residential: Yes — required for homes with irrigation systems or other cross-connections
- Who can test: Certified tester
- Enforcement: DEQ regulations; local water utility
Water Heater Installation
A permit is required to replace or install a water heater in Michigan.
- Licensed plumber required: No — homeowner exemption available
- Homeowner can DIY: Yes, for primary residence (permit still required in most areas)
- Note: Homeowner can obtain permit for own home
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
- Minimum 18" clearance from floor for gas heaters in garages
- Expansion tank often required when backflow preventer is installed on main supply
Homeowner DIY Plumbing Rights
Michigan allows homeowners to perform plumbing work on their primary residence.
Homeowner exemption for primary residence
Water Conservation Requirements
Michigan follows federal water conservation minimums (no additional state mandates).
Federal minimums apply
Lead Service Line Replacement
Under the revised EPA Lead and Copper Rule (2021), Michigan is required to inventory lead service lines and develop replacement plans.
Aggressive replacement mandate (Flint legacy); 5-year replacement requirement
Important Disclaimer
This information is provided as a general overview. Plumbing codes and regulations can vary significantly between municipalities within Michigan. 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
- EPA Safe Drinking Water Act — Cross-Connection Control Program
- State building departments