Building permits, zoning and septic rules in Wheatland County, Montana

A single-family residence in unincorporated Wheatland County generally does not need a state building permit unless a local government requires one by ordinance or resolution¹. Farm and ranch buildings and private owner-use garages or storage buildings are also exempt from the state permit requirement³. Montana nevertheless enforces a uniform statewide building code for residential and commercial buildings; a permit exemption is not the same as having no code².

Montana requires a building permit before certain non-exempt new construction, alterations, additions and repairs begin³. Projects subject to the state program receive inspections required by Montana law, and the permit holder must notify the inspector when work is ready^3,7. Separate plumbing, mechanical or electrical permits may still be required, so describe the complete project to the Montana Building Codes Program before work starts³.

Wheatland County's department listing does not identify a county building department, and the county appears not to require a residential building permit in unincorporated areas¹³. For a non-exempt project under state jurisdiction, contact the Montana Building Codes Program at (406) 841-2056 or buildingcodes@mt.gov³. The state office specifically invites applicants to ask when they are unsure whether a building needs a permit³.

For a covered project, submit the application and construction plans to the state program³. The reviewer calculates valuation and fees, checks the plans, communicates deficiencies and issues the permit after compliance and full payment; review can take from a few hours to several weeks¹. The separate plan-review fee is 35 percent of the building-permit fee¹.

Wheatland County has a Planning Board that meets quarterly, but we could not confirm whether a countywide zoning ordinance governs unincorporated parcels^5,8. Montana law allows counties to adopt zoning, but that authority alone does not show that Wheatland County has done so¹⁴. Harlowton does have local zoning: its Planning and Zoning Commission reviews zoning amendments, site plans and plat applications⁶.

For an unincorporated parcel, ask the Wheatland County Planning Board about zoning, setbacks, minimum lot and dwelling size, building height and lot coverage^5,8. For land inside Harlowton, ask the city about its Land Development Code and building-code requirements⁶. In either location, subdivision sanitation review and septic approval are separate from zoning^4,15.

Central Montana Health District administers Wheatland County's septic program, including permits and inspections for DEQ-regulated systems⁴. A new system costs $475 with a certified installer or $650 with an uncertified installer, including the site visit; other published fees vary by system and installer¹⁶. A state Certificate of Subdivision Approval does not replace the local drainfield permit¹⁵.

Only about 23.9% of Wheatland County soils are rated without severe limitations for a conventional septic drain field, so do not assume a standard system will work before a site evaluation¹². For subdivisions with lots greater than 20 acres, the district review asks for water and sanitation information and requires at least 4 feet of vertical separation below a new onsite system; groundwater within 7 feet triggers additional evidence¹⁷. Contact the district at 406-566-2277 before choosing a house site¹⁸.

We could not confirm a countywide rule for long-term RV living, temporary camping on private land or tiny-home occupancy in Wheatland County⁵. The Montana rule limiting stays at Fish, Wildlife & Parks public-use sites applies only to those public sites and does not answer whether someone may occupy an RV on private property¹⁹.

Ask the Wheatland County Planning Board for a written, parcel-specific answer before moving an RV or tiny home onto unincorporated land⁸. Inside Harlowton, the city's zoning and land-development rules apply⁶. A development with permanent recreational-vehicle spaces may also trigger subdivision sanitation review regardless of parcel size, and a tiny home may need a septic permit even when no state building permit is required^1,15.

1. Email the Wheatland County Planning Board with the parcel number and ask whether zoning, setbacks, floodplain review or subdivision conditions apply; inside Harlowton, confirm city zoning too^5,6,8.
2. If land is being divided, determine whether state or district sanitation review applies; DEQ reviews divisions creating parcels under 20 acres, while Central Montana Health District has a review for lots greater than 20 acres^15,17.
3. Confirm wastewater feasibility with Central Montana Health District and obtain the septic permit before installation⁴.
4. Describe the building and trades to the Montana Building Codes Program; a single-family home may be permit-exempt, while covered projects require plan review and inspection^1,3,7.
5. If a state building permit is required, submit plans and the application, resolve review comments and pay all fees before construction^1,3.
6. Check state-highway access and DNRC water-right requirements before driveway or well work^11,20.

Start with septic feasibility: only about 23.9% of county soils avoid severe limitations for a conventional drain field, making an early site evaluation valuable¹². Water planning matters too because Wheatland County averages about 16.2 inches of precipitation annually and has experienced severe drought in about 12.1% of years¹². A qualifying groundwater development may use Montana's permit exception, but specified exceptions require a Notice of Intent beginning in 2026¹¹.

Confirm legal access and whether a driveway will intersect a state highway, which triggers MDT approach review²⁰. Ask the Planning Board about zoning and mapped flood risk because Wheatland County's parcel-level zoning and floodplain requirements were not confirmed^5,8. If the parcel comes from a subdivision, obtain its sanitation approval and recorded plat; the county charges a $25 base filing fee plus per-lot charges for subdivision plats²¹.