The best answer to this question comes from MN Rules, Chapter 1300 - the administrative section of the building code:
1300.0120 PERMITS.
Subpart 1.  Required. An owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert, or replace any gas, mechanical, electrical, plumbing system, or other equipment, the installation of which is regulated by the code; or cause any such work to be done, shall first make application to the building official and obtain the required permit.