Building permits, zoning and land rules in Hill County, Montana

A single-family home in unincorporated Hill County does not require a state structural building permit; Montana also exempts farm and ranch buildings, residential buildings with fewer than five dwelling units unless they serve transient guests, and qualifying private garages and storage buildings¹. The exemption is only from the state building permit: a farm or ranch building may still face zoning, subdivision, floodplain or septic rules⁹. Montana has adopted the 2024 International Building Code and International Residential Code for areas under the State Building Codes Bureau, including non-certified areas of Hill County¹⁰. Covered non-exempt work goes through the state building-permit program and receives state building inspections; the permit holder must notify the inspector when work is ready and provide access⁹. Hill County separately requires a $75 zoning permit for work outside city limits within the City-County Planning area².

For covered non-exempt construction in unincorporated Hill County, use the Montana Building Codes Program for the state building permit and building inspections^1,9. State building-permit fees use the applicable valuation method, and the plan-review fee is 35 percent of the building-permit fee¹. Inside Havre, the city handles building permits; Hill County Environmental Health still handles septic permits countywide^3,5. For county zoning approval, call the Hill County Planning Office at 406-740-7250 or email kangland@greatwesteng.com². The $75 zoning permit covers work outside city limits within the City-County Planning area, but we could not confirm a complete county application, review, inspection or appeal procedure².

Hill County has zoning, but the confirmed zoning-permit rule covers work outside city limits within the City-County Planning area rather than every unincorporated parcel². Ask the Planning Office to confirm whether a tract lies inside that area before relying on the county process². We could not confirm the planning-area boundaries, setbacks, minimum lot size, minimum dwelling size or lot-coverage limits, so ask Planning for the parcel's district and dimensional standards². Hill County regulates land division through county subdivision regulations and the Montana Subdivision and Platting Act, both administered by the Planning Office². Inside Havre, the city sets zoning by district; Hill County Environmental Health remains the septic-permit authority^4,5.

Hill County Environmental Health administers individual sewage permits throughout Hill County, including properties inside city limits⁵. A septic permit is required before installing a new system or modifying or updating an existing system⁵. The office can be reached at 406-400-2366 or environmentalhealth@hillcounty.us, and its page asks callers to leave a voicemail for county staff⁵. A Montana Certificate of Subdivision Approval does not replace the local drainfield permit¹¹. Site conditions deserve early attention because only 8.4% of Hill County soils are rated without severe limitations for a conventional septic drain field⁸. We could not confirm Hill County's septic inspection sequence or fee, so ask Environmental Health about site evaluation, design, inspections and the current charge before choosing a house site⁵.

We could not confirm a Hill County rule that gives a general yes-or-no answer for long-term RV occupancy or tiny-home occupancy on private rural land². Work outside city limits within the City-County Planning area requires a county zoning permit, so ask the Planning Office how the parcel's district treats an RV residence, a tiny home on a foundation, a tiny home on wheels and an accessory dwelling². A tiny home that needs a new septic system or changes an existing system must obtain a Hill County septic permit⁵. We also could not confirm a minimum dwelling size, so get that standard from Planning before selecting a structure².

1. Ask the Hill County Planning Office whether the parcel is in the City-County Planning area and whether subdivision or floodplain review applies².

1. Obtain the $75 zoning permit before work if the site is outside city limits within that planning area².

1. Confirm the building-permit authority: Havre runs its certified program inside city limits, while covered non-exempt work in unincorporated Hill County goes to the Montana Building Codes Program; a single-family home there is exempt from the state structural building permit^1,3.

1. For a covered state project, submit the building-permit application and plans, pay the building-permit and plan-review fees, and arrange required building inspections^1,9.

1. Evaluate the septic area early because only 8.4% of county soils lack severe limitations for a conventional drain field⁸.

1. Obtain the Hill County septic permit before installing or changing the system; Environmental Health handles that septic permit countywide⁵.

Ask Hill County Planning about zoning, subdivision status and floodplain review before closing². Hill County averages about 12.8 inches of precipitation a year, and severe drought occurs in 14.8% of years, so a dependable water plan matters⁸. New or expanded groundwater use generally requires a Montana water-use permit, though a small groundwater development may qualify for an exception; beginning January 1, 2026, the state requires a Notice of Intent before using water under a permit exception⁷. Only 8.4% of county soils lack severe limitations for a conventional septic drain field, so make septic feasibility part of the purchase contingency⁸. Hill County administers floodplain regulations, but we could not confirm local thresholds or the approval process; ask Planning whether the parcel needs floodplain review². A new or modified approach onto a state highway requires an approach permit or right-of-way agreement from the appropriate Montana Department of Transportation district office¹².