Building permits, zoning and land rules in Ozaukee County, Wisconsin

Yes. Wisconsin's Uniform Dwelling Code applies to new one- and two-family dwellings, including manufactured-home installations, in Ozaukee County¹. A UDC permit is required for stick-built, modular and manufactured-home installations, and the delegated municipality issues it or DSPS does when the municipality lacks authority¹. The application includes plans, required project data, the fee and contractor information when applicable¹. Required inspections cover footings, foundation, rough work, insulation and final work; notify the inspector identified on the UDC permit¹. An owner who occupies or will occupy the completed home may take out the construction and erosion-control permits without Dwelling Contractor certification, but plumbing and electrical work stay under licensed-professional rules and the allowance does not waive code, permit or inspection requirements^5,8. Detached garages and accessory buildings fall outside the UDC, so ask the parcel's municipality what permit they need⁵. Like the counties around it, Ozaukee County requires a building permit⁹.

Ozaukee County has no single building counter for every new home; the delegated municipality administers the UDC permit, or DSPS does when the municipality lacks authority¹. Start with the parcel's town, village or city to identify the correct permit issuer and inspector⁹. The Town of Grafton's Building Inspector is one local example, not a countywide office: Grafton requires the proper permit when a contractor or homeowner performs work on a home, and contractors usually pull their own permits⁹. Grafton lists a fence as its only permit exception as of March 2023⁹. During UDC construction, call for each inspection before covering the work; the inspector has two business days after the request and the work is ready before it may be covered⁵. Building permits come from the municipality or DSPS, but septic permits and shoreland and floodplain zoning approvals stay with the Ozaukee County Land & Water Management Department^2,3.

Ozaukee County does not apply general county zoning to all private land; towns, villages and cities handle general zoning, while the county handles shoreland and floodplain zoning in unincorporated areas². County zoning applies within 300 feet of a stream, within 1,000 feet of a lake or flowage, or in a floodplain extending beyond those distances². The county floodplain ordinance divides regulated land into Floodway, Floodfringe, General Floodplain, Coastal Floodplain and Flood Storage districts¹⁰. County shoreland districts have minimum lot sizes, lot widths and water setbacks, though the available rules do not supply a single numeric standard for every parcel, and municipal rules may be stricter⁶. Floodplain subdivision proposals, including manufactured-home parks, must include regional flood-elevation and floodway data¹¹. Starting shoreland or floodplain work without the county permit is a violation¹⁰. The Village of Newburg, which lies mainly in Washington County and reaches into Ozaukee County, sets its own zoning code¹². Ask the parcel's municipality about allowed uses, RVs, tiny homes, ordinary setbacks, minimum home size, height and lot coverage outside the county's limited jurisdiction².

The Ozaukee County Land & Water Management Department administers the county sanitation ordinance, and sanitary regulation applies to all unsewered development in Ozaukee County³. Submit the sanitary permit application to the appropriate governmental unit before obtaining a permit for a private onsite wastewater treatment system; the county form covers new, replacement, modified, holding-tank, in-ground, at-grade and mound systems⁴. Systems installed or modified through this process must be installed, inspected, tested, operated and maintained under the applicable state rules and operation manual⁴. All wastewater from unsewered development must discharge into the POWTS, so an off-grid plan does not bypass county sanitary review¹³. Only 6.9% of Ozaukee County soils rate free of severe limitations for a conventional drain field, making a parcel-specific site evaluation important before assuming a conventional system will work⁷. A UDC home using a private well also needs a well permit from the county or municipality⁵.

We could not confirm a countywide rule allowing long-term RV or tiny-home occupancy on private land in Ozaukee County. The parcel's town, village or city handles general zoning outside the county's limited shoreland and floodplain jurisdiction, so ask that municipality whether the proposed unit, placement and occupancy are allowed². County sanitary regulation applies to all unsewered development, and all wastewater must discharge into the approved POWTS, so discuss the sanitation plan with the Ozaukee County Land & Water Management Department before occupying the site¹³. A manufactured-home installation used as a residence is subject to the UDC permit requirement¹. For a UDC-covered dwelling, occupancy follows a final inspection with no major health or safety violations; some municipalities also issue an occupancy permit⁵. We could not confirm a countywide minimum dwelling size, temporary-camping rule or tiny-home occupancy rule, making the parcel's municipality the essential first call.

1. Identify the parcel's town, village or city, then confirm its zoning and whether that municipality or DSPS administers the UDC permit^1,2.
2. Ask the municipality about allowed use, setbacks, minimum dimensions and permits for work outside the UDC's one- and two-family scope¹.
3. For an unsewered site, submit the required sanitary application through the Ozaukee County process before obtaining the sanitary permit⁴.
4. Obtain a county or municipal well permit if the UDC home will use a private well⁵.
5. If unincorporated land is in a county shoreland or floodplain district, obtain the applicable approval before development^2,10.
6. Submit the UDC application, plans, required project data, fee and contractor information when applicable¹.
7. Call the permit's inspector for the footing, foundation, rough, insulation and final inspections¹.
8. Occupy the dwelling only after a final inspection finds no major health or safety violations, and ask whether the municipality issues an occupancy permit⁵.

Identify the parcel's town, village or city before buying because that municipality generally decides permitted uses and dimensional rules². Check whether unincorporated land falls within 300 feet of a stream, within 1,000 feet of a lake or flowage, or in a floodplain extending farther; those locations bring county shoreland or floodplain zoning into the review². County permit fees are $50 for a shoreland permit, $250 for a floodplain permit and $0.25 per square foot of structure footprint, and starting work before the permit is issued can bring fees up to ten times the applicable charges¹⁴. Obtain a septic site evaluation early because only 6.9% of county soils rate free of severe limitations for a conventional drain field⁷. Confirm wastewater and private-well permits before committing to an unsewered parcel^4,5. A driveway connecting to a state highway requires a WisDOT permit, while we could not confirm a countywide local-road access rule¹⁵. The typical property-tax bill is about $4,629 per year at an effective rate near 1.3%⁷.