Duluth, MN Building Safety: Plumbing Permits (2026)

Section 10-32 of the Duluth Legislative Code requires a separate permit from the building official before anyone installs, alters, or otherwise works on plumbing in a building or structure, or on any premises connected to that plumbing; the code exempts only stoppage removal, leak repairs, and replacement of fixtures and appurtenances. A private sewer or house drain also needs its own permit and cannot be covered over or used until the building official inspects and approves it. Section 10-33 sets the application procedure: the applicant files on official forms furnished by the building official, states the total estimated cost of the work, pays the permit fee under Section 10-2 of the Chapter, and submits whatever plans and specifications the building official requires.

Section 10-34 limits who can hold the permit: except as otherwise provided, the building official cannot issue a plumbing permit unless the applicant is licensed by the State of Minnesota as a plumbing contractor, though an owner-occupant of a single-family dwelling may get a permit to do plumbing work on that home without a master plumber's license, with the exception of installing or replacing house sewers. Anyone doing plumbing work for another person in Duluth must hold a Minnesota license, except an apprentice working under a licensed plumber's direct supervision, and a licensed plumber must carry that license during working hours and produce it on request from the building official or the property owner.

1 layers on a separate backflow-preventer program: installation, maintenance, and testing follow the Minnesota State Plumbing Code, annual testing is required by the Minnesota State Building Code, and property owners get 30 days after notice from the building official to have a state-certified tester complete the work and report results.