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

At a glance

Building permit

Not required for a single-family home in state jurisdiction unless a local ordinance or resolution requires one¹

Building inspections

Montana Building Codes Program inspects projects that require a state permit³

Zoning

Reported as no comprehensive county zoning outside incorporated areas; ask Planning about the parcel⁴

Septic

County permit required; get a Planning Department address before issuance²

RV or tiny-home living

Private-land occupancy rules could not be confirmed; ask Community Development & Planning⁵

Owner-builder

Limited plumbing exemption when the homeowner personally does the work for a personal residence⁶

County-road driveway

$125 approach permit required before work begins⁷

Who to call

Contact details are copied from each office’s official page and were checked against it on September 28, 2026.

Do you need a building permit in Broadwater County, Montana?

A single-family residence in the parts of Broadwater County under Montana state building-permit jurisdiction does not need a building permit unless a local government requires one by ordinance or resolution¹. State law also exempts farm and ranch buildings, residential buildings with fewer than five dwelling units unless they serve transient guests, and owner-used private garages and storage buildings that are not part of a business¹. Separate electrical, plumbing and mechanical permits may still be required¹.

For covered work, Montana requires a state permit for certain new buildings, alterations, additions and repairs⁸. The Montana Building Codes Program performs inspections on projects requiring a state permit, and the permit holder must notify the inspector when work is ready³. Do not treat the residential exemption as a blanket exemption for every structure or trade permit.

Who handles building permits in Broadwater County?

Broadwater County Community Development & Planning provides land-use guidance and property addressing from the county courthouse⁵. Reach the office at (406) 266-9211 or [email protected]⁵. For a project covered by Montana's state permit program, submit the construction plans and Building Permit/Plan Review Application to the Montana Building Codes Program⁹. The state issues the permit after plan-review comments are resolved and fees are paid, and separate trade permits may apply⁹.

Start with the county Planning office even when the house itself is exempt from a building permit. The county requires an address from Planning before Environmental Health can issue a septic permit². If a state building permit is required, obtain it before the related plumbing, mechanical or electrical permits and before that work starts⁸.

Does Broadwater County have zoning?

Broadwater County is reported as having subdivision regulations and a growth policy but no comprehensive county zoning outside incorporated areas⁴. The county's current official pages do not publish a clear countywide zoning statement, so ask Community Development & Planning for a parcel-specific answer before relying on that general description⁵. Montana law allows a county commission with an adopted growth policy to adopt zoning for all or part of its jurisdiction¹⁰.

Lack of comprehensive zoning would not erase the other development controls that apply to a parcel. Broadwater County regulates subdivisions, while Montana DEQ reviews covered divisions creating parcels smaller than 20 acres and recreational camping-vehicle or mobile-home parks regardless of parcel size¹¹. New development within a designated Special Flood Hazard Area needs a floodplain permit¹². Minimum dwelling size, setbacks, building height and lot coverage could not be confirmed; ask Planning about the exact parcel⁵.

How do septic permits work in Broadwater County?

Broadwater County Environmental Health & Sanitarian issues the local on-site wastewater permit¹³. Obtain a Planning Department address before the septic permit is issued². Do not begin dirt work, well drilling, foundations or other construction first, because doing so doubles the septic permit fee². Reach Environmental Health at (406) 266-9209 or [email protected]¹⁴.

The published application lists $250 with a certified installer, $350 with a non-certified installer and $100 for tank replacement only¹⁵. It also lists a $300 site evaluation when the property exceeds 20 acres or lacks a DEQ Certificate of Subdivision Approval¹⁵. A Certificate of Subdivision Approval does not replace the local drainfield permit¹⁶. Only 23.5% of county soils are rated without severe limits for a conventional drain field, so make septic feasibility a purchase contingency rather than assuming a conventional layout will work¹⁷.

Can you live in an RV or tiny home in Broadwater County?

Broadwater County's rules for living in an RV or tiny home on private land could not be confirmed. Ask Community Development & Planning about the parcel, the proposed duration and whether the site is inside an incorporated municipality before moving in⁵. The reported absence of comprehensive county zoning outside incorporated areas is not, by itself, permission for residential occupancy⁴.

Montana's published camping-duration limits apply to Fish, Wildlife & Parks public-use sites, not private land¹⁸. A recreational camping-vehicle park is a different question: Montana DEQ reviews those parks regardless of parcel size as part of subdivision sanitation review¹¹. A tiny home may also trigger septic, floodplain and trade-permit requirements depending on the site and work proposed²¹²¹. The county has not confirmed a minimum home size or a private-land camping limit, so Planning is the office to ask⁵.

What are the steps to build a home in Broadwater County?

1. Ask Community Development & Planning for land-use guidance and obtain the property address⁵².
2. Apply to Environmental Health for the septic permit before dirt work, well drilling or foundation work begins².
3. Ask the local Floodplain Administrator whether the site lies in a designated Special Flood Hazard Area; covered development there needs a permit¹².
4. Determine whether the structure is exempt or needs a Montana state building permit, and identify any separate electrical, plumbing or mechanical permits¹.
5. If a state permit applies, submit plans and the application; issuance follows satisfactory plan review and full fee payment¹⁹.
6. For access onto a county road, submit the county approach application and $125 fee before starting work⁷. For a new or changed approach onto a state highway, apply through the appropriate Montana Department of Transportation district office²⁰.

What should you check before buying land in Broadwater County?

Check septic feasibility first: only 23.5% of Broadwater County soils are rated without severe limits for a conventional drain field¹⁷. Confirm legal access and whether the driveway meets a county road or a state highway, because those approaches use different permitting authorities⁷²⁰. Ask the local Floodplain Administrator whether any designated Special Flood Hazard Area affects the build site¹².

Water deserves equal attention. Broadwater County averages 15.4 inches of precipitation annually and has experienced severe drought in about 13.2% of years, so verify the well, water right and intended supply rather than relying on the seller's description²¹²². Private-well permitting and mandatory utility-connection rules could not be confirmed. For carrying costs, the median property-tax bill is about $2,210 a year and the effective property-tax rate is about 0.6%²³²⁴. Finally, verify any deed restrictions or subdivision approvals that apply to the particular tract.

Watch-outs

• A homeowner who personally performs plumbing in a personal residence may avoid the state plumbing permit only if the home is not speculative construction or intended as a rental; the exemption does not waive other permits⁶.
• Starting dirt work, well drilling, foundations or other construction before Broadwater County issues the septic permit doubles that permit fee².
• A county-road approach requires the application and $125 fee before work begins; a state-highway approach goes through the Montana Department of Transportation instead⁷²⁰.

Sources

1. Frequently Asked Questions, quoted and re-checked
2. Environmental Health & Sanitarian, quoted and re-checked
3. Building Permits (Montana statewide rule), quoted and re-checked
4. Broadwater County 2020 Growth Policy (2026 county census)
5. Broadwater County Community Development & Planning (broadwatercountymt.gov)
6. Plumbing Permits, quoted and re-checked
7. Broadwater County Public Works Department (broadwatercountymt.gov)
8. Building Permits (Montana statewide rule), quoted and re-checked
9. Building Permits (Montana statewide rule), quoted and re-checked
10. 76-2-201. County zoning authorized, MCA (Montana statewide rule), quoted and re-checked
11. Final Subdivision Regulations - Adopted 2021Nov29, quoted and re-checked
12. Stream Permitting, quoted and re-checked
13. Environmental Health & Sanitarian (2026 county census)
14. Broadwater County Environmental Health & Sanitarian (broadwatercountymt.gov)
15. Broadwater County Environmental Health Office — septic application (townsendmt.com)
16. Engineering Infrastructure & Subdivisions (Montana statewide rule), quoted and re-checked
17. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
18. Public Use Rules and Regulations (Montana statewide rule), quoted and re-checked
19. Frequently Asked Questions, quoted and re-checked
20. Approach Manual for Landowners and Developers (Montana statewide rule), quoted and re-checked
21. Annual precipitation: Bolthole Index county data
22. Share of years in severe drought: Bolthole Index county data
23. Median property tax bill: Bolthole Index county data
24. Effective property tax rate: Bolthole Index county data

Written September 28, 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.