The Quick Answer
This is the DIY plumbing guide for Michigan we’d want someone to read before they spend a weekend attempting a plumbing project that turns into an emergency call on Monday. Michigan’s plumbing code is specific, and the distinction between legal homeowner work and work requiring a license isn’t always obvious from YouTube tutorials or home improvement forums.
Michigan homeowners can legally perform a range of basic plumbing repairs on their own homes without a license or permit; this includes faucet replacement, toilet flapper repair, showerhead swaps, and simple fixture maintenance. A licensed plumber must perform any work involving new pipe runs, drain-waste-vent systems, gas lines, water heater installation, or work requiring a permit. This guide gives you a clear, honest line between what’s legal DIY and what isn’t.
We’re being honest here because we believe informed homeowners make better decisions — and because the most common time we get an emergency call from a DIYer is after they’ve discovered that what they thought was a simple repair was actually regulated work they weren’t equipped to complete safely.
For urgent service needs, contact Kenowa Plumbing.
The Legal Framework: Michigan’s Plumbing Licensing Law
Michigan regulates plumbing work under the Skilled Trades Regulation Act (Public Act 407 of 2016) and the Michigan Plumbing Code. The key provisions that affect homeowners:
⚖️ What the Michigan Skilled Trades Regulation Act Says
Michigan requires a licensed master plumber or journeyman plumber (working under a master) to perform plumbing work that requires a permit. A homeowner may perform plumbing work on their own primary residence — the home they live in — without a license, but only for work that does not require a permit and only on that single-family primary residence. Rental properties, commercial properties, and work that requires a permit are outside this homeowner exemption.
📋 When a Permit Is Required
Michigan requires a plumbing permit for: installation of new plumbing systems, extension or alteration of existing systems, replacement of water heaters, new or relocated drain-waste-vent piping, and gas line work. Simple repairs and like-for-like replacements of fixtures in the same location typically do not require a permit. When in doubt, contact your local building department — Grand Rapids, Kentwood, and Wyoming all have permit offices that answer homeowner questions.
| The homeowner exemption in Michigan applies only to your primary single-family residence — not rental properties, not a second home, not a property you’re flipping. If you own a rental property and do your own plumbing work without a license, you may be in violation of both the Skilled Trades Regulation Act and your landlord obligations under MCL 554.139. |
What Michigan Homeowners CAN Do Themselves
The following repairs are generally within the scope of legal homeowner DIY work in Michigan
✅ Faucet and Fixture Repair & Replacement
Replacing a dripping faucet, swapping a showerhead, and replacing a toilet flapper or fill valve are all homeowner-appropriate repairs. These involve disconnecting and reconnecting supply lines and don’t involve new pipe runs or permit-required work.
✅ Like-for-Like Toilet Replacement
Replacing a toilet in the same location does not require a permit in most Michigan municipalities. This is achievable for a mechanically comfortable homeowner.
✅ Supply Line Replacement
Replacing the braided stainless supply lines under sinks and behind toilets — the flexible tubes connecting shutoff valves to fixtures — is straightforward homeowner work. Turn off the shutoff valve, unscrew both ends, replace, hand-tighten plus a quarter turn, and check for leaks.
✅ Drain Cleaning (Fixture-Level)
Clearing a clogged drain at the fixture level — removing the P-trap under a sink, clearing hair from a shower drain, snaking a sink drain with a hand snake — is legal homeowner work.
✅ Aerator and Showerhead Cleaning
Removing, cleaning, and reinstalling aerators (the small screen at the end of a faucet) and showerheads — especially important in West Michigan’s hard water environment where scale buildup reduces flow — is routine homeowner maintenance.
✅ Shutoff Valve Operation
Locating and exercising shutoff valves (turning them off and back on) to confirm they operate is homeowner maintenance, not regulated work. Every homeowner should know where their main shutoff and individual fixture shutoffs are.
What Michigan Homeowners CANNOT Do Without a License
The following categories require a licensed plumber in Michigan — regardless of how confident you feel about your plumbing abilities:
🚫 New Pipe Runs, Extensions, or Drain-Waste-Vent Work
Any work that involves running new supply lines, extending existing lines, adding new drain connections, or modifying the drain-waste-vent system requires a licensed plumber and a permit. This includes: adding a bathroom, relocating a sink or toilet, running a new gas line, adding an outdoor irrigation supply connection, or any work that adds to or changes the pipe infrastructure of the home.
🚫 Water Heater Replacement
Michigan requires a plumbing permit for water heater replacement, which means licensed contractor work. The permit covers the gas connection, the T&P valve installation, the supply and discharge connections, and the venting. An unpermitted installation impinges upon home sale. Insurance claims can also flag during home inspection.
🚫 All Gas Line Work
Natural gas lines are not homeowner DIY territory in Michigan — period. Any work on gas supply lines, appliance connections, or new gas line runs requires a licensed plumber or gas fitter. See our full gas line guide for details.
🚫 Work on Rental Properties (Any Plumbing)
The homeowner exemption in Michigan does not apply to rental properties. Even simple repairs on a rental property technically require a licensed contractor. Beyond legality, Michigan’s Landlord-Tenant Act creates liability for landlords who perform their own unlicensed repairs on rental units.
🚫 Main Sewer Line Work
Any work on the sewer lateral (the line from the house to the municipal main) requires a licensed plumber/permit. This includes sewer camera inspections using professional equipment, trenchless lining, pipe bursting, and open-cut replacement.
🚫 Installing or Relocating Shutoff Valves on Main Supply Lines
Adding a shutoff valve to the main supply line or making changes to the main supply connection is regulated work. Individual fixture shutoff valves can be replaced by homeowners; main line shutoffs and pressure regulators require a licensed plumber.
The Risks of Unpermitted or Unlicensed Plumbing Work
Beyond the immediate safety risks, unpermitted plumbing work creates downstream problems that many Michigan homeowners don’t anticipate:
🏠 Home Sale Complications
Michigan home sales include a seller disclosure requirement. Unpermitted improvements — including unpermitted water heater installations, added bathrooms, or plumbing modifications — must be disclosed. Buyers and their inspectors frequently identify unpermitted work, and it can result in price renegotiation, required remediation before closing, or a failed sale.
🛡️ Insurance Claim Denial
Homeowner’s insurance policies typically include a clause excluding coverage for damage resulting from work that required a permit but didn’t have one. If a water heater fails and floods your basement, and the insurance company discovers it was installed without a permit, your claim may be partially or fully denied.
🔧 Code Compliance Costs at Refinancing
Lenders sometimes require updated appraisals or inspections during refinancing. If an appraiser or inspector identifies unpermitted work, the lender may require correction before finalizing the refinance. The cost of retroactive permit compliance often exceeds what the original licensed installation would have cost.
Frequently Asked Questions
Retroactive permitting is possible in Grand Rapids and most Michigan municipalities — contact your local building department about a post-installation permit. The inspector will assess the installation, may require corrections, and once approved will document the installation. While the process isn’t free or easy, it’s far better than discovering the issue at home sale time.
A like-for-like hose bib swap (same location, same connection) is generally considered within homeowner DIY scope in Michigan. If you’re converting from a standard to a frost-free model (which requires cutting into the supply pipe inside the wall), that’s regulated plumbing work in most municipalities. When in doubt, call your local building department or Kenowa Plumbing.
A plumbing license is a credential held by an individual (master plumber or journeyman plumber) certifying their qualifications to perform regulated plumbing work. A plumbing permit is a project-specific authorization issued by a municipality for a specific scope of work at a specific property. Regulated plumbing work requires both: a licensed person performing the work and a permit for the specific project.
Many plumbing repairs genuinely are straightforward. The legal question isn’t about difficulty — it’s about code compliance, safety, and documentation. A water heater installation that goes wrong (improperly vented, incorrect T&P valve, failed gas connection) can create a carbon monoxide hazard or a gas leak. Permits exist to ensure someone with verified training confirms the work is safe. The permit inspection is the check on the licensed contractor’s work.
