Michigan HVAC: mechanical contractor licenses, permits and homeowner work
Source: Local Help Stations (localhelpstations.com). Last updated November 2, 2026.
Heating and cooling work in Michigan falls under the Michigan Mechanical Code and the mechanical contractor article of the Skilled Trades Regulation Act.
What Michigan rules say
- Installing, altering or servicing HVAC equipment, ductwork, refrigeration and heating service work takes a mechanical contractor license with the right classification. (source: Michigan Department of Licensing and Regulatory Affairs)
- State law lists ten classifications, including HVAC equipment, ductwork, refrigeration, and limited or unlimited heating service. (source: Michigan Legislature)
- To sit for a classification exam, an applicant generally needs at least 3 years or 6,000 hours of experience in that work. (source: Michigan Legislature)
- Apart from replacing minor parts, mechanical work may not start until the enforcing agency issues a permit. (source: Michigan Department of Licensing and Regulatory Affairs)
- Portable heaters and coolers, and window air conditioners of 1.5 horsepower or less, do not need a permit. (source: Michigan Department of Licensing and Regulatory Affairs)
- An owner who lives in a single family home may install a heating or cooling system without a license, but must affirm ownership on the permit application and get the inspection once the system runs. (source: Michigan Legislature)
- Permits for low pressure steam boilers in homes must be pulled by a contractor licensed for hydronic heating and cooling and process piping. (source: Michigan Department of Licensing and Regulatory Affairs)
This page covers statewide rules only. Cities and counties can add their own permits and licenses, so check with your local building office too.
More Michigan topics
Sources
- Michigan Department of Licensing and Regulatory Affairs (LARA), Bureau of Construction Codes: Mechanical Permit Information (checked November 2, 2026)
- Michigan Legislature (legislature.mi.gov): MCL 339.5807, Skilled Trades Regulation Act: mechanical contractor classifications (statute text) (checked November 2, 2026)
- Michigan Legislature (legislature.mi.gov): MCL 339.5819, Skilled Trades Regulation Act: heating or refrigerating system installed by the owner of a single family dwelling (statute text) (checked November 2, 2026)
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