No local government in Beaverhead County is certified to enforce the building code, so a house with fewer than 5 dwelling units needs no building permit here, and commercial buildings are permitted by the Montana Building Codes Program (406-841-2056). Beaverhead County Land Services, at 2 South Pacific Street in Dillon, issues the County’s own land use permits, and County Environmental Health charges $200 for a conventional septic permit.
What needs a permit in Beaverhead County?
The State’s list of certified building-code jurisdictions has no entry for Beaverhead County, Dillon or Lima. That leaves the state rules in charge everywhere in the county:
State building permit
- Commercial buildings, new or altered
- Residential buildings with 5 or more dwelling units
- Smaller residential buildings that serve transient guests
- Changes of occupancy and moved buildings of those kinds
No building permit
- Houses and other residential buildings with fewer than 5 units
- Farm and ranch buildings
- Private garages and storage buildings kept for the owner’s own use
- Mining buildings on mining property
An exempt house can still need County approvals. Land Services lists 5 land use permits, each tied to a place or a use:
- Big Hole River permit: for any roofed structure built or structurally altered within 500 feet of the river’s ordinary high water mark.
- Floodplain permit: for work in a regulated flood hazard area.
- Dillon Airport Affected Area permit: for a new structure taller than 30 feet, or one raised above 30 feet, inside the mapped Permit Required Area.
- Wireless communications facilities: an application reported to the County Commission.
- Buildings for rent or lease: reviewed under the County’s own regulations.
A new or altered septic system needs a County Environmental Health permit, and a new driveway onto a county road needs an approach permit from the Road Department.
Who issues permits in Beaverhead County?
County offices at 2 South Pacific Street, Dillon, share the local side of the work, and the state office in Helena covers the building code.
Short on time to read all of this?
Get a free quote →| Office | What it handles | Contact |
|---|---|---|
| Land Services (Planner) | Floodplain, Big Hole River, airport-area, wireless and rent-or-lease permits; subdivisions | Suite 7; 406-683-3768; Monday to Friday, 8:00 a.m. to 5:00 p.m. |
| Environmental Health (Sanitarians) | Septic permits and installer licences | Second floor of the courthouse; 406-683-3771; Monday to Friday, 8:00 a.m. to noon and 1:00 to 5:00 p.m. |
| Road Department | Approach permits on county roads | Suite 13; 406-683-3780 |
| GIS and Rural Addressing | Addresses outside Dillon and Lima | 406-683-3757 |
| Montana Building Codes Program | State building, electrical, plumbing and mechanical permits | 406-841-2056; buildingcodes@mt.gov |
Dillon (population 4,271) is not a certified city. Before any construction inside city limits, the City requires a Zoning Compliance Certificate from City Hall, 125 North Idaho Street (406-683-4245). Its application states that a commercial building permit can only come from the State and that the applicant must arrange state electrical and plumbing inspections.
Lima (population 221) is not certified either, so the same state rules apply. County Land Services provides planning staff support to the Town, and the Town office answers on 406-276-3521.
Applications and how to file them
Beaverhead County has no permit portal. County forms are PDFs returned to the office that issues the permit; state permits are filed through the State’s online permit system or on paper.
- Big Hole River permit application: Exhibit A of Ordinance 2005-1, filed with Land Services.
- Floodplain Permit Application: the County uses Montana’s Joint Application for work in streams, wetlands and floodplains, and posts the instructions beside it.
- Airport Affected Area permit or variance: issued by the Planner acting as AAA Administrative Officer.
- Wireless Communication Facilities Application and Variance Application: on the Land Services page.
- Application for On-Site Waste Water Treatment Permit: filed with Environmental Health; a separate form registers septic installers.
- Approach Permit Application: filed with the Road Department with a location map.
- State Building Permit/Plan Review Application, and state electrical, plumbing and mechanical permit applications.
Inside Dillon, the City publishes its own Zoning Compliance, Fence Permit and Sign Permit applications.
Permit fees in Beaverhead County
Because no County building permit exists, the local costs are the land use, septic and city zoning fees below.
Not sure this scope needs a permit?
Get a free quote →| Permit | Fee |
|---|---|
| Big Hole River permit | No review fee; a variance application is $100 |
| Dillon Airport Affected Area permit | $0; $100 for a variance request |
| Septic permit, conventional system | $200 |
| Septic permit, replacement system or rewrite | $100 |
| Septic system not installed by a licensed installer | $100 added |
| Dillon zoning certificate, single-family home or accessory dwelling unit | $200 |
| Dillon zoning certificate, accessory structure | $75 |
| Dillon zoning certificate, deck, fence, shed or greenhouse | $35 |
| Dillon zoning certificate, commercial building | $250 up to 5,000 sq ft; $500 up to 10,000 sq ft; $1,000 up to 45,000 sq ft |
| Dillon review of floodplain use | $200 |
| Dillon water and sewer system development | $725 water and $1,120 sewer per equivalent dwelling unit |
The septic figures are printed on the County’s current application, which adds that other fees may apply. Dillon’s figures come from the City Fee Schedule 2025 and its 2026 zoning application; a certificate applied for after the work has started costs twice the normal fee. The County floodplain ordinance leaves its permit fee to the fee schedule adopted by the County Commissioners.
Electrical, plumbing and mechanical permits
All three trades are state permits in Beaverhead County, including inside Dillon and Lima, and a house that is exempt from a building permit still needs a state electrical permit for its wiring. Applications go to the Montana Building Codes Program (406-841-2056).
Rather talk it over?
Call 1-855-478-4290 →What to submit
County septic permit
- Owner, legal description, property size and the year the survey was filed
- Installer’s name and whether the system is new or a replacement
- Number of bedrooms and bathrooms, and whether a basement has plumbing
- A sketch of the system with lot boundaries, buildings, wells, waterways and roads, showing where a 100% replacement drainfield can go
- For lots without a state certificate of sanitary approval or larger than 20 acres: at least 2 percolation tests, test pit results or the NRCS soil survey, 3 or more nearby well logs and a nitrate test of well water
Dillon zoning certificate
- 2 sets of a site plan, with one electronic copy if possible
- Property corners and dimensions, existing and proposed structures with square footage and height
- Setbacks (the form lists 25 feet front, 10 feet side and 10 feet rear)
- Curb cuts, driveways, easements, parking and landscaping
- Sewer and water lines with the point of connection
- A Will-Serve Letter from the City
For a state building permit, the Building Codes Program asks for construction plans with its Building Permit/Plan Review Application and publishes a Commercial Building Checklist. It reports an average plan review of about 3 weeks.
How to get a project permitted: 6 steps
Work out whether the site is inside Dillon, inside Lima or in the unincorporated county; Dillon adds a zoning certificate, and the County assigns addresses only outside the 2 towns.
Use the County’s interactive floodplain map and the Airport Affected Area map, and measure the distance to the Big Hole River if the land is near it.
File the Big Hole River, floodplain or airport-area application at Suite 7 before building.
Environmental Health must issue the septic permit before the system is built, and the Road Supervisor has 72 hours to inspect and approve an approach application.
Send commercial plans to the Building Codes Program, and take out state electrical and plumbing permits for the trades.
Book each inspection with the agency that issued the permit, and ask GIS and Rural Addressing for the address.
Rather not deal with the Beaverhead County building department?
Get a free quote →Inspections
No County building inspector exists, so the inspections on a project follow the permits. On a state building permit, the permit holder calls the state inspector at least 24 hours before the inspection is wanted, and the inspector has 72 hours from that call to carry it out. State electrical permit holders call for rough-in and final inspections and give 48 hours’ notice before covering the work.
County Environmental Health inspects septic installations, and the County Road Supervisor inspects a new approach when it is finished. Dillon’s zoning certificate is a zoning review, and the City leaves building code inspections to the State.
Local rules worth knowing
Big Hole River: Ordinance 2005-1 sets a building setback of 150 feet or more from the ordinary high water mark. The 500-foot figure is the area the ordinance covers, not the setback. Planning staff decide within 20 working days of a complete application, and may require an independent engineering review at the applicant’s cost for sites near the floodplain. Irrigation structures and fences are not covered.
Floodplain: the County’s Floodplain Hazard Management Regulations took effect on September 14, 2023 and rely on flood maps dated August 15, 2023. The State’s instructions for the joint application give about 60 days for a floodplain permit and say other required permits must be issued first. The septic application lists the Floodplain Administrator on 406-683-3724.
Dillon Airport: the Airport Affected Area Regulations (Ordinance 2008-01) also cover new trees expected to grow taller than 30 feet in the Permit Required Area.
County road approaches: an approach must be 24 feet wide, meet the road at a right angle and have 600 feet of sight distance each way. Off a paved county or state road it must be paved back to the right-of-way line.
Subdivisions: the County Planning Board meets on the second Thursday of each month at 1:00 p.m. in the Commissioners’ Room of the courthouse, under Subdivision Regulations revised in 2024.
Montana building code
Montana adopts one building code, based on the 2024 International Codes from 26 September 2026; a certified local program or the state Building Codes Program enforces it, and the state code does not reach houses of fewer than five units, farm and ranch buildings or private garages unless a local government has made it apply to them. How Montana’s statewide code works
Official permitting resources for Beaverhead County
These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.
Want this handled start to finish?
Get a free quote →- Montana effective construction code editions
- Montana certified local building programs
- Montana DLI state building permit application
- Beaverhead County Land Services (Planner): land use permits and forms
- Big Hole River Conservation Development Standards (Ordinance 2005-1) and application
- Dillon Airport Affected Area Regulations (Ordinance 2008-01)
- Beaverhead County Floodplain Hazard Management Regulations (Ordinance 2023-03)
- Beaverhead County Environmental Health (septic permits)
- Beaverhead County septic permit application and fees
- Beaverhead County Road Department
- Beaverhead County approach permit application
- Beaverhead County GIS and Rural Addressing
- City of Dillon documents: zoning application and fee schedule
- City of Dillon Planning & Zoning
Inspections are where schedules slip.
Get a free quote →Beaverhead County permit FAQs
Do I need a building permit to build a house in Beaverhead County?
No. Neither the County nor Dillon or Lima runs a certified building-code program, and the State does not require a building permit for a residential building with fewer than 5 dwelling units. You still need state electrical and plumbing permits where they apply, a County septic permit, and a Dillon Zoning Compliance Certificate inside the city.
Who issues commercial building permits in Dillon?
The Montana Building Codes Program in Helena (406-841-2056). The City of Dillon issues a Zoning Compliance Certificate first and says commercial construction must not begin until the state building permit has been secured.
How much is a septic permit in Beaverhead County?
$200 for a conventional system and $100 for a replacement system or a rewrite, plus $100 if the system is not installed by a licensed installer.
How close to the Big Hole River can I build?
The County requires a setback of at least 150 feet from the ordinary high water mark, and a County permit for any structure within 500 feet of it. A smaller setback needs a variance, which costs $100 to apply for.
Do I need a permit for a fence or shed in Dillon?
Yes. Dillon requires a zoning permit before any fence is built, and its fee schedule charges $35 for a fence, deck, shed or greenhouse.
What does a Dillon Zoning Compliance Certificate cost for a new home?
$200 for a single-family residence of any size, with water and sewer system development fees charged separately.
Where do I get a rural address?
From the County’s GIS and Rural Addressing Department (406-683-3757) for property outside the city limits of Dillon and Lima.
Simplify Beaverhead County permitting with Alliance Permitting
Alliance Permitting is a permit documentation and submission company in Montana. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.
Ready to break ground in Beaverhead County sooner?
Let Alliance prepare, file, and track your Beaverhead County permits while your crew stays on the job.
More Montana permitting guides
This guide is provided by Alliance Permitting for general information about Beaverhead County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.