Mich. Comp. Laws § 290.618
The sealer of a city or a county, and his deputy sealers, supervising inspectors, and city or county inspectors when acting under his instructions and at his direction, shall have the same powers and shall perform the same duties within the city or the county for which appointed as are granted to and imposed upon the director by this act, except that the jurisdiction of a county sealer shall not extend to any city for which a city sealer has been appointed as provided for by section 17.
No city or county shall adopt any ordinance contrary to or in any way conflicting with this act, or adopt any regulation contrary to or in any way differing from the provisions of any regulations adopted by the director under the provisions of this act.
MCL 290.618