Lake County does not issue building-code permits. Outside Polson and Ronan no local building program is certified, so commercial buildings and residential buildings of five or more units take a State of Montana permit, and a house with fewer than five units needs no State building permit. What the County does require comes from the Lake County Planning Department: a $250 zoning conformance permit in its zoning districts, lakeshore permits of $200 to $800 on Flathead Lake, Lake Mary Ronan and Swan Lake, floodplain permits and building notification permits, all filed in Cloudpermit. Septic permits ($400 for a new system) come from Lake County Environmental Health.
What needs a permit in Lake County?
Three questions decide the answer on unincorporated land: is the parcel in one of the County’s zoning districts, is it on a lakeshore or in a mapped floodplain, and is the building one the State regulates. The County and the State each permit their own part.
Lake County Planning
- Zoning conformance permit before any work, use or construction in a County zoning district
- Lakeshore construction permit for work within 20 horizontal feet of high water on Flathead Lake, Lake Mary Ronan or Swan Lake
- Floodplain permit for projects in the regulated floodplain, from a domestic well or utility line to a bridge
- Building notification permit on subdivision lots whose plat approval calls for one
- Sign permits and airport affected area structure or use permits
State of Montana
- Building permit for commercial buildings and for residential buildings with five or more dwelling units
- Electrical permit for all wiring
- Plumbing permit for work done by a plumber
- Mechanical permit on buildings that need a State building permit
No State building permit
- Residential buildings with fewer than five dwelling units, unless they serve transient guests
- Farm and ranch buildings
- Private garages and storage buildings for the owner’s own use
No lakeshore permit
- Minor maintenance costing less than $10,000 over five years
- Boat lifts, uncovered or with removable covers
- Boat rails and mooring buoys that meet the design standards
Zoning rules differ by district. In the East Shore district, for example, a structure under 100 square feet needs no zoning conformance permit unless it sits within 50 feet of the Flathead Lake high-water mark, and every application must include a stormwater management plan. A septic permit from Environmental Health is needed before any wastewater system is installed, altered or replaced.
Who issues permits in Lake County?
The Planning Department handles subdivision review, zoning, building notification, lakeshore construction and floodplain permits for land under County jurisdiction. Tiffani Murphy is the Planning Director. Neither the County nor the Town of St. Ignatius appears on the State’s list of certified building-code programs (updated October 7, 2026), so the State Building Codes Program is the building-code authority there.
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Get a free quote →| Detail | Information |
|---|---|
| Land-use permits | Lake County Planning Department |
| Address | Dave Stipe Annex Building, 500 1st St E, Polson, MT 59860 |
| Phone and email | 406-883-7235, planning@lakemt.gov |
| Office note | Closes at 3:15 p.m. on the second Wednesday of each month for board meetings |
| Septic permits | Lake County Environmental Health, same building, 406-883-7236 |
| Road approaches | Lake County Road Department, 406-883-7206 |
| Building code permits | Montana Building Codes Program, 406-841-2056 |
The county has three incorporated municipalities:
- Polson: the City’s Building Department permits and inspects new and remodel work inside city limits, covering building, electrical, mechanical, plumbing and fire requirements. Applications are filed online through GovWell, and the plan review fee is paid at submittal. One City form, the Zoning Conformance & Building Permit Application, covers the zoning sign-off as well: under the Planning and Public Works Fee Schedule effective January 15, 2026, zoning conformance review costs $150 for a residential project and $500 for a commercial one, plus $50 per hour after 3 hours. A fence needs a $50 fencing application, and the City has its own lakeshore, demolition and structure relocation permits. The Building Official’s line is 406-883-8216.
- Ronan: the City issues its own building permits inside city limits and publishes an application, a list of exempt work and a fee worksheet (adopted March 3, 2020 and posted as updated September 23, 2022). The worksheet starts at $35 for work valued up to $1,999 and adds a 20% plan review fee on projects valued over $5,000. The application goes to the City Clerk’s office with a site plan that shows the zoning setbacks, and the City Code also requires a zoning conformance permit from the Zoning Officer, applied for with or before the building permit, and a Zoning Officer’s permit to move or demolish a building. Work started without a permit pays an investigation fee equal to the permit fee on top of it. Ronan is certified for building only, so electrical, plumbing and mechanical permits there come from the State. City Hall is at 406-676-4231.
- St. Ignatius: the State is the building-code authority. The Town’s zoning ordinance requires a zoning permit from its Zoning Administrator before a building is erected, placed, moved, expanded or structurally altered. The ordinance’s fee summary lists $25 for a single-family home and $50 for anything else, and a zoning permit runs for one year from approval. Town Hall is at 12 1st Ave, 406-745-3791.
Around Polson, the City/County zoning district is administered by the City inside its limits and by County Planning outside them, each under its own version of the Polson Development Code.
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Get a free quote →Permit types and online filing
All Planning Department applications are submitted and permitted online in Cloudpermit, except subdivision exemptions and survey review. An account lets you follow the application, message the planner assigned to it, and see outstanding requirements and remaining fees. If you would rather have staff enter your materials into the system, the fee schedule charges $25 for that.
- Zoning conformance permit (ZCP): issued under the regulations of the district the parcel is in. Thirteen of the county’s 16 zoning districts are run by County Planning, among them East Shore, Finley Point, Kings Point, Lake Mary Ronan, Masumola, Melita Island Road, South Ronan, Swan Sites and Upper West Shore.
- Lakeshore construction permit: for docks, shore stations, retaining walls, fill and other work in the lakeshore protection zone. A lakeshore variance has no form; you upload a written narrative that answers the criteria in the regulations.
- Floodplain permit: priced by the size of the project, with the State joint application used for work in streams.
- Building notification permit: a County check that construction on a platted subdivision lot follows the conditions of the subdivision’s approval, such as building location, setbacks, driveways and buffers.
- Zoning variance: has its own online application in Cloudpermit.
Amendments and extensions of existing permits have no separate application; call the Planning Department to arrange them. State building, electrical, plumbing and mechanical permits are applied for on the State’s online permit site or on its paper forms.
Lake County permit fees
These figures come from the Planning Department Fee Schedule that took effect on March 1, 2026.
| Permit | Fee |
|---|---|
| Zoning conformance permit | $250 |
| Building notification permit | $250 |
| Lakeshore construction permit, project cost up to $1,500 | $200 |
| Lakeshore, $1,501 to $5,000 | $350 |
| Lakeshore, $5,001 to $10,000 | $500 |
| Lakeshore, $10,001 to $25,000 | $650 |
| Lakeshore, $25,001 and greater | $800 |
| Floodplain, small-scale project (up to 1,000 cubic feet of material, a domestic well, water or utility lines) | $350 |
| Floodplain, mid-scale project (more than 1,000 to 15,000 cubic feet) | $550 |
| Floodplain, large-scale project (bridges, levees, dams, channel work) | $850 |
| Sign permit, County | $250 |
| Sign permit, Polson Development Code area | $200 plus $0.25 per sq ft |
| Airport affected area structure or use permit | $200 |
| Conditional or special use permit | $400, plus $150 for issuance of the permit |
| Variance (one request) | $600, plus $150 for issuance of the permit |
| Extension of a zoning, lakeshore, floodplain or building notification permit | $75 |
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Call 1-855-478-4290 →Work done without a permit is charged an after-the-fact fee on top of the normal one: $650 plus the application fee for a zoning conformance permit, a building notification permit or lakeshore work that did not disturb the lakebed. Each further violation by the same owner adds $150. Card payments carry a charge of 3% of the bill plus $0.30.
Septic permits are priced separately by Environmental Health: $400 for a new or replacement system, $200 for an alteration and $100 for a vacation rental review, with $100 for a second or later inspection.
Electrical, plumbing, mechanical and septic permits
Electrical, plumbing and mechanical: Polson issues its own trade permits and inspects the work. On unincorporated land, in Ronan and in St. Ignatius, the trade permits are State permits and State inspectors do the inspections.
Septic: every wastewater system installed, altered or repaired on fee land needs an installation or alteration permit from Lake County Environmental Health before work starts. The system must be designed by a professional engineer or registered sanitarian licensed in Montana, and the County keeps a list of licensed installers. Adding living quarters or turning a house into a vacation rental counts as an alteration even when nothing is dug up.
Application documents
Cloudpermit lists the uploads each Planning application needs. Two submittals are set out in County documents:
Septic permit application
- Owner details, legal description and a location map or directions
- Floor plans for each level of every structure with living quarters, with rooms labeled
- Scaled site plan with a north arrow, property lines, structures, driveways, utility lines, wells and surface water within 100 feet of the property lines
- System design to DEQ Circular 4: soil profile, design flow, tank and drainfield specifications
- Percolation test and groundwater monitoring results where required
- Agent certification form if an agent signs, and a check payable to Lake County Environmental Health
Zoning conformance permit (East Shore example)
- Application signed by a holder of an interest in the property
- The review fee
- Stormwater management plan sized from the total impervious surface
- Buffer strip design plan for lakefront parcels
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Get a free quote →How to apply: 6 steps for a Lake County project
Work out whether it is inside Polson, Ronan or St. Ignatius, in a County zoning district, on a lakeshore or in the floodplain, and whether it is fee land or trust land.
Planning staff discuss projects by appointment only; call 406-883-7235 or email planning@lakemt.gov.
Create an account, choose the zoning, lakeshore, floodplain or building notification application and upload the documents it lists.
Send the wastewater application, design and fee to Environmental Health before construction begins.
Apply to the State for the building permit if the building is commercial or has five or more units, and for electrical and plumbing permits.
Use the Road Department’s 2026 road approach permit form for a new driveway onto a County road.
Inspections and follow-up
Lake County does not carry out building-code inspections. Planning staff may visit the site while reviewing a zoning, lakeshore or floodplain application, and the fee schedule prices some amendments by whether a site visit is needed ($100 without, $150 with). Environmental Health inspects septic installations; a second or later inspection costs $100, and an alteration permit can only be issued for a system that already holds a valid use permit.
State inspectors cover State-issued permits; Polson and Ronan inspect under their own.
Local Lake County details that matter
Flathead Indian Reservation: most of Lake County lies inside the reservation. Land held in Tribal or individual trust status is exempt from County land-use regulations, and the County’s wastewater rules apply only to property held in fee status.
Flathead Lake: the County’s lakeshore regulations, updated February 1, 2026, do not cover the part of the lake in the City of Polson’s jurisdiction or the waters below elevation 2,893.2 feet inside the reservation. After-the-fact lakeshore work that disturbed the lakebed, in the County’s area off the reservation, is charged $850.
Groundwater monitoring: Environmental Health may require monitoring at the proposed drainfield during spring runoff, April 1 to July 1, so a septic design started in summer can wait until the next season.
Polson fringe: signs and wireless facilities in the City/County zoning district outside Polson use the County’s Polson Development Code forms.
Floodplain: the County’s Floodplain Management Regulations took effect on February 6, 2013.
Want this handled start to finish?
Get a free quote →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 Lake County
These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.
- Montana effective construction code editions
- Montana certified local building programs
- Montana DLI state building permit application
- Lake County Planning forms and fees
- Lake County Planning Department
- Lake County Planning Department Fee Schedule (effective March 1, 2026)
- Lake County Cloudpermit portal
- Lake County zoning districts and regulations
- Lake County lakeshore protection regulations
- Lake County floodplain permits
- Lake County Environmental Health wastewater (septic) permits
- Lake County Road Department permits
- Montana electrical permits
- City of Polson Building Department
- City of Polson building permits and applications (zoning conformance, fence, lakeshore, demolition)
- City of Polson fee schedules effective January 15, 2026
- City of Ronan Building Department
- City of Ronan ordinances (City Code, Titles 4 and 10)
- Town of St. Ignatius website
- Town of St. Ignatius Zoning Ordinance, June 2000 (PDF on the Lake County site)
Inspections are where schedules slip.
Get a free quote →Lake County permit FAQs
Does Lake County issue building permits?
No. The County issues zoning conformance, lakeshore, floodplain and building notification permits, but building-code permits outside Polson and Ronan come from the State of Montana.
Do I need a building permit for a house in Lake County?
Not a building-code permit if the house is outside Polson and Ronan and has fewer than five dwelling units. You may still need a County zoning conformance, lakeshore or floodplain permit, a septic permit and a State electrical permit.
How much is a zoning conformance permit?
$250 under the fee schedule effective March 1, 2026. Building without one costs $650 plus the application fee.
What does a dock or lakeshore permit cost on Flathead Lake?
Between $200 and $800, depending on the cost of the project: $200 up to $1,500 and $800 for $25,001 and greater.
How do I apply for a Lake County permit?
Online in Cloudpermit. Only subdivision exemptions and survey reviews are handled outside the portal.
Who issues septic permits?
Lake County Environmental Health, 406-883-7236. A new or replacement system permit is $400 and an alteration permit is $200.
Who issues building permits in Polson, Ronan and St. Ignatius?
Polson and Ronan issue their own inside city limits, and each also requires a zoning conformance approval: $150 or $500 in Polson, and in Ronan a zoning conformance permit from the City’s Zoning Officer. St. Ignatius is not a certified building jurisdiction, so the State rules apply there, and the Town requires its own zoning permit, $25 for a single-family home.
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More Montana permitting guides
This guide is provided by Alliance Permitting for general information about Lake County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.