Electrical permits are required for all new electrical wiring and additions to existing systems. Electrical permits are not required for minor repair work. Under the Michigan Electrical Administrative Act of 1956-338-8891, Definitions Sec. 1 (9), "minor repair work" means electrical wiring not in excess of a valuation of $100.
Most plumbing work on construction projects - no matter the size or scale - requires a permit.
Mechanical work on construction projects - no matter the size or scale - requires a permit, with some exceptions.