Construction Services & Inspections

Commercial Plumbing Permits & Reviews

Plumbing plans may need to be reviewed by the state of Minnesota’s Department of Labor and Industries Plumbing Section or city of Duluth Construction Services. When plumbing plan review is required, plumbing permits will not be issued and work may not begin until plans have been reviewed and approved and a permit issued. If you have questions about plumbing plan review or commercial plumbing permits, give us a call and we’ll put you in contact with a plumbing inspector.

Reviews by city of Duluth Construction Services

Unless review by MN DOLI Plumbing Section is required, Duluth CSI will review plumbing plans for:

  • All projects which include a food service facility;
  • All other projects with more than 25 fixture openings, unless reviewed by DOLI as described above.

  Except: One- and two- family dwellings and townhomes regulated by the MN Residential Code.

Plumbing permit applications must be accompanied by two sets of plumbing plans prepared by a mechanical engineer or master plumber.

Duluth Plumbing Plan Submittal Requirements

  • A plumbing permit application
  • Two copies of plumbing plans prepared by a mechanical engineer or master plumber
  • The design professional in charge of the project, usually the architect, must indicate the plans are consistent with other building plans. This indication may be made directly on the plans or may be in a written statement specifying the plan preparer and date of latest revision.
  • Plans must include the following information:
    • Floor plan (show fixtures. horizontal waste piping/pipe sizes)
    • Roof plan (if internally piped roof drains are proposed)
    • Water riser diagrams (isometric preferred)
    • Soil, waste and vent riser diagrams (isometric preferred )
    • Utility site plan (for all site plumbing, including storm to point of discharge)
    • Point of building stormwater plumbing discharge clearly identified
    • Plumbing specification
    • Designer’s printed name, email address, phone number, license number and signature

Plumbing permits for reviewed projects will not be issued until the plan review is complete and approved. The approved plans must be available to the plumbing inspector on the job site for all inspections.

Reviews by the Minnesota Department of Labor and Industries, Plumbing Section

Review by MN DOLI Plumbing Section is required for:

  • Licensed Health Care Facilities
    Plumbing plans for licensed health care facilities regulated by the Minnesota Department of Health must be submitted to the Minnesota Department of Labor & Industry (DLI) for review. This applies to all plumbing plans for hospitals, nursing homes, supervised living facilities, free-standing outpatient surgical centers, correctional facilities, boarding care homes, or residential hospices, and similar state-licensed facilities;
  • Public Buildings Owned by the State
    Public buildings which are owned and paid for by the state or a state agency, regardless of cost, and school district building projects or charter school building projects, regardless of cost must be submitted to DLI.
  • Projects of a Special Nature
    Projects of a special nature, including dialysis facilities and other projects for which a department plan review is requested by either the municipality or the state, must be submitted to DLI.

    Information Minnesota DOLI Plumbing Section plan reviews can be found here. 

    After the MN DOLI Plumbing Section has approved the plumbing plans, a plumbing permit application may be made to the city of Duluth. The city of Duluth will issue plumbing permits and inspect work for state-reviewed projects. The city of Duluth plumbing permit application submittal must include:

    • A plumbing permit application, and
    • A copy of the approval letter from MN DOLI Plumbing Section, and
    • TWO COPIES of the plans referenced in the MN DOLI approval letter.