Building permits, zoning and septic rules in Marathon County, Wisconsin

At a glance

Building permit

Required for a new one- or two-family home; apply to the delegated local authority or DSPS¹

County zoning

General county zoning applies only in participating towns; cities and villages have separate jurisdiction⁵

Septic (POWTS) permit

County CPZ administers private sewage systems, with state requirements also applying⁴

Owner-builder exemption

An owner who currently occupies or will occupy the home may take out the UDC construction and erosion-control permits themselves⁶

RV living

Recreational use is conditional in county-zoned towns; permanent habitation is prohibited⁷⁸

Minimum lot size

Varies by district and utility service in towns under county zoning⁹

Septic inspection

State rule requires a visual inspection at least once every 3 years¹⁰

Private well

A state notification number is generally required before drilling a new non-high-capacity well¹¹

Who to call

Contact details are copied from each office’s official page and were checked against it on October 15, 2026.

Do you need a building permit in Marathon County, Wisconsin?

Wisconsin's Uniform Dwelling Code (UDC) applies statewide to new one- and two-family homes in Marathon County, including manufactured homes¹². The code covers new homes built since 1980 and specified additions and alterations; older homes, accessory structures and buildings with three or more residential units may fall under different rules, so ask the inspector before assuming a barn or shed is covered¹³. A UDC building permit is required for a new stick-built, modular or manufactured-home installation¹. Plans must be approved and the building permit issued and posted before construction begins; a new home on private septic also needs its sanitary permit before the building permit can be issued¹⁴. Required inspections cover footings, foundation and reinforcement, rough electrical, plumbing, HVAC and framing work, insulation, and final inspection¹⁵¹⁶. The inspector may be a delegated municipality's or a DSPS-appointed inspector, and the one named on the UDC permit is the person to notify¹⁷. Request each inspection before covering the work; the inspector has 2 business days after the request and the work is ready to inspect before the work may be covered, subject to the local inspector's instructions¹⁸. Occupancy requires a final inspection with no major health or safety violations; some municipalities issue occupancy permits¹⁹.

Who issues building permits in Marathon County, and how do you reach them?

A delegated town, village or city issues the UDC building permit and performs building inspections; where the municipality lacks delegated authority, submit the building-permit application to Wisconsin DSPS through eSLA and use its Inspector Look-Up Tool²³. The application must include plans, required data, contractor information where applicable and the building-permit fee²⁰. Building-permit authority does not change septic authority: Marathon County Conservation, Planning and Zoning (CPZ) handles septic permits countywide⁴. For county zoning approval and septic permits, call CPZ at 715-261-6000 or cpz@marathoncounty.gov, at 1100 Lake View Drive, Suite 400, Wausau, WI 54403²¹. CPZ administers shoreland, floodplain, airport-overlay, POWTS and mining ordinances countywide, while general county zoning applies only after a town adopts it²². Cities and villages have separate zoning jurisdiction⁵.

Does Marathon County have zoning, and what does that mean for your land?

General county zoning applies to unincorporated Marathon County only in towns that adopted it⁵. Inside Schofield and the Village of Rothschild, each municipality administers its own zoning; Marathon County CPZ remains the septic-permit authority²³²⁴⁴. The county publishes district standards and maps for participating towns; use those maps to confirm where county zoning approval is required²⁵. In participating towns, minimum lot size, lot coverage, setbacks and building height depend on the district; shoreland or floodplain rules may also apply^9262728. A new or expanding manufactured-home park in the county's manufactured-home park district requires conditional-use approval and must satisfy park and lot standards²⁹. Shoreland, floodplain, airport-overlay and mining ordinances remain with CPZ even where general county zoning does not apply²². In an unincorporated shoreland area, buildings generally must be at least 75 feet from the ordinary high-water mark, subject to listed exceptions and setback averaging³⁰.

How do septic permits work in Marathon County?

Marathon County CPZ administers the county private sewage system ordinance, while state POWTS requirements also apply⁴. Every private sewage system needs its own application and sanitary permit before installation, replacement, repair, reconnection or modification; minor repairs are excepted³¹. A county sanitary permit is also required before constructing or installing a non-plumbing sanitation system³¹. POWTS construction and installation must be inspected under the plan-review approval letter; contact the agency that issued the permit when the system is ready³². Once a system is in service, state rule requires a visual inspection at least once every three years, and an anaerobic tank must be pumped when combined sludge and scum reach about a third of its volume¹⁰. Only about 11.6% of Marathon County soils are free of severe limitations for a conventional drain field, so obtain a site evaluation before assuming a standard field will work³³.

Can you live in an RV or tiny home on your land in Marathon County?

On unincorporated parcels subject to Marathon County Chapter 17 zoning, RV use may be allowed for recreation, but permanent habitation is prohibited, and the ordinance passage we reviewed identifies no exception allowing it⁸³⁴. Do not assume recreational use authorizes living in an RV while building; ask CPZ about the proposed use before relying on that arrangement³⁵²¹. RV storage requires a principal structure in a Residential or Agricultural district; wetlands and some floodplain areas exclude RVs, and a compliant self-contained sanitary system or designated POWTS is required⁷. Private/personal use is limited to 3 RVs per parcel unless the Zoning Administrator approves otherwise; parking longer than 180 days requires screening from the road right-of-way⁷. Keep wheels attached except for repairs and do not fix the RV to the ground in a way that prevents immediate removal⁷. Outside county-zoned towns, ask the applicable town, city or village about RV use³⁶. We could not confirm a countywide tiny-home occupancy rule; ask CPZ in a county-zoned town or the local municipality elsewhere²¹. In county-zoned towns, manufactured homes are allowed where single-family dwellings are allowed principal uses, subject to an 800-square-foot minimum and installation and design standards³⁷.

Building a home in Marathon County: the steps, in order

1. Use the county zoning maps or call CPZ to determine whether county or town zoning governs the parcel²⁵²¹.

1. Obtain the applicable zoning approval before applying for the building permit³⁸.

1. If the home will use private septic, obtain the county sanitary permit before construction and before the building permit; obtain any applicable well permit too³¹³⁹¹⁴.

1. Submit the building-permit application, contractor-license information, plans, required data and fee to the delegated local authority or DSPS⁴⁰.

1. An owner who occupies or will occupy the home may take out the construction and erosion-control permits, but the permits and code requirements still apply⁴¹.

1. Obtain driveway approval from the town for a town road, the Marathon County Highway Department for a county road, or WisDOT for a state or federal highway⁴².

1. Notify the inspector named on the UDC permit for the footings, foundation and reinforcement, rough work, insulation and final building inspections³.

What to check before you buy land in Marathon County

Confirm whether the town your parcel sits in has opted into Marathon County Zoning or zones itself; that changes who handles zoning, though CPZ remains the septic contact²¹⁴³. Get a soils evaluation before you rely on a specific septic layout: only about 11.6% of Marathon County's soils are free of severe limitations for a conventional drain field, while 97.8% of the county's land has slopes of 15% or less³³⁴⁴. If the parcel is near water, measure the 75-foot shoreland setback from the ordinary high-water mark before siting a structure³⁰. County shoreland and floodplain rules apply across unincorporated Marathon County, and town rules may be stricter⁴⁵. Check mapped floodway and floodfringe areas: floodway development is largely prohibited, and floodfringe structures need their first floor at least two feet above base flood elevation⁴⁶. Confirm road ownership before planning access because the town, county Highway Department or WisDOT issues the driveway approval accordingly⁴². Land-division and addressing fees have their own county schedule; do not assume those figures cover building, zoning or septic permits⁴⁷.

Watch-outs

• General Marathon County zoning applies only in participating towns; CPZ also administers shoreland, floodplain and POWTS ordinances, so confirm the parcel’s zoning jurisdiction before choosing a building or RV site²²²⁵.
• On parcels governed by Marathon County Chapter 17, permanent RV habitation is prohibited and no exception allowing it was identified; other towns, cities and villages may have different rules³⁴⁵.
• We could not confirm a countywide tiny-home occupancy rule; ask CPZ in a county-zoned town or the local municipality elsewhere²¹⁴³.

Sources

1. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
2. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
3. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
4. Zoning & Regulatory Programs, quoted and re-checked
5. Zoning & Regulatory Programs, quoted and re-checked
6. Instructions for Submitting a UDC Permit Application, quoted and re-checked
7. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
8. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
9. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
10. Wisconsin Maintenance Program (Wisconsin statewide rule), quoted and re-checked
11. Well and heat exchange notification (Wisconsin statewide rule), quoted and re-checked
12. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
13. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
14. Wisconsin’s Uniform Dwelling Code (Wisconsin statewide rule), quoted and re-checked
15. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
16. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
17. UDC inspection requirements, quoted and re-checked
18. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
19. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
20. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
21. Marathon County Conservation, Planning and Zoning (CPZ) Department (marathoncounty.gov)
22. Marathon County Conservation, Planning and Zoning (CPZ) Department – Regulatory Programs (marathoncounty.gov)
23. Schofield: Planning & Zoning (Marathon County), quoted and re-checked
24. Village of Rothschild: Chapter 590 Zoning (Marathon County), quoted and re-checked
25. Marathon County Comprehensive Plan 2026 Working Draft, quoted and re-checked
26. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
27. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
28. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
29. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
30. Wisconsin’s Shoreland Management Program (Wisconsin statewide rule), quoted and re-checked
31. General Code of Ordinances for Marathon County, Chapter 15 — Private Sewage System, quoted and re-checked
32. Private Onsite Wastewater Treatment Systems (POWTS), quoted and re-checked
33. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
34. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
35. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
36. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
37. General Code of Ordinances for Marathon County Chapter 17 – Zoning Code, quoted and re-checked
38. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
39. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
40. UDC (Uniform Dwelling Code / One- and Two-Family Dwellings), quoted and re-checked
41. Wisconsin’s Uniform Dwelling Code, quoted and re-checked
42. County Addressing, quoted and re-checked
43. Marathon County Zoning (2026 county census)
44. Share of land at 15% slope or less: Bolthole Index county data
45. Marathon County Comprehensive Plan 2026 Working Draft, quoted and re-checked
46. Floodplain Development Basics (Wisconsin statewide rule), quoted and re-checked
47. Marathon County: Land Division (Chapter 18) & Addressing Fee Schedule, quoted and re-checked

Written October 15, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.