Lincoln County, Montana Building Permit Guide

There is no county building permit in Lincoln County. The Lincoln County Planning Department administers the subdivision, floodplain, lakeshore construction and buildings-for-lease-or-rent regulations, with floodplain and lakeshore permits priced at $250 to $750. Commercial buildings are permitted by the State Building Codes Program everywhere in the county, and a home with fewer than five units needs a building permit only inside Libby or Troy, whose city inspectors cover residential work. Forms are emailed or delivered to the Planning office at 512 California Avenue in Libby.

What needs a permit in Lincoln County?

Outside the city limits of Libby and Troy, the permits that apply to a building project are a mix of County, Health Department and State approvals.

The City of Libby states the position plainly for owners just outside its boundary: no City building permit is needed, though State or County permits may still apply to electrical, plumbing, mechanical and septic work.

Who issues permits in Lincoln County?

Lincoln County is not on the State’s list of certified building-code programs (updated October 7, 2026), and its Planning Department does not issue building permits. Planning provides land-use services to the County and to the towns of Troy, Eureka and Rexford. The department recently moved into the main courthouse building.

The four incorporated places split into two groups:

• Libby and Troy are certified by the State for residential building permits (and pools) inside their city limits. Each has a city Building Inspector. Troy’s code gives its inspector 30 working days to finish plan review and leaves permit fees to City Council resolution; it also requires a manufactured home building permit before a unit is placed, and a floodplain development permit from the City’s floodplain administrator before work starts in a mapped floodplain. Libby’s Municipal Code sets the same 30 working days for plan review, and the City requires a no-cost permit from City Hall before a sidewalk is removed, replaced or built. It also posts street opening and tree removal permit forms. Commercial building permits in both cities, and all electrical, plumbing and mechanical permits, come from the State.
• Eureka and Rexford are not certified, so the State is the only building-code authority and a house with fewer than five units needs no building permit. Eureka’s Town Hall is open Monday to Friday, 8:30 a.m. to 4:30 p.m.; the Town says its ordinances are being updated and will be posted once codified.

Permit types and how to file

Lincoln County has no online permit portal. Planning forms can be filled in on screen and emailed to the department, or printed and delivered in person or by mail with the fee. The department notes that some forms still show old fee amounts, and that the fee schedule governs.

• Lakeshore construction application: a 2026 fillable form for docks, shoreline work and anything else in the lakeshore protection zone.
• Floodplain joint application: the multi-agency form and its instructions, used for work in the floodplain and in streams.
• Floodplain interpolation request: a free County check of whether a property or structure is in the floodplain, available before you buy or build.
• Pre-application meeting request: the first step for a subdivision.
• Lincoln County road approach: the form for a driveway or other access onto a County road.
• Airport influence area construction permit: for building inside an airport influence area.
• Family transfer and other exemption applications: for land divisions that skip full subdivision review.

In Libby, the City publishes its building permit requirements and application as PDFs and also hands them out at City Hall. Contractors working in Libby must hold a City business licence before starting.

Lincoln County permit fees

The Planning Department Fee Schedule took effect on April 1, 2024 and is the one posted as current. Floodplain and lakeshore permits are priced as a range, and staff set the amount during the sufficiency review according to the scale of the project and the review time expected.

Inside Libby, the City puts the cost of a residential building permit at approximately 1% of the total construction value. Starting without a permit adds 50% of the combined plan review and permit fee, with a $250 minimum and a $1,000 maximum.

Electrical, plumbing, mechanical and septic permits

No local government in Lincoln County is certified for the trades, so electrical, plumbing and mechanical permits are State permits in the unincorporated county and in all four municipalities. Libby’s own page says so for work inside the city.

Septic permits belong to the Lincoln County Health Department. A local wastewater permit is always required before a system is installed, the site evaluation must be done by a qualified site evaluator, and the design has to follow DEQ Circular 4. Only an installer licensed by Lincoln County may build or alter a system, with one exception: a homeowner putting in a gravity system for their own residence on their own land.

Application documents

What you assemble depends on which office you are dealing with.

For a septic permit, the Health Department takes its Septic System Application (April 2026 form) with the fee; applications are not reviewed until the fee is paid.

How to apply: 6 steps in Lincoln County

Inspections

Planning does not inspect buildings. Its floodplain rules can still lead to enforcement: the County may fine an owner and require removal of improvements built in the floodplain without permits. The Health Department inspects septic installations and charges $150 for a site visit.

Libby’s Building Inspector works by appointment and reviews and inspects residential projects inside the city; sidewalks and driveways there are exempt from permits but are still inspected. Troy’s Building Inspector is reached through City Hall, which is open Monday to Friday, 8:00 a.m. to 5:00 p.m. State inspectors handle electrical, plumbing and mechanical work and every State building permit.

Local Lincoln County details that matter

Libby asbestos: homes and businesses in and around Libby may contain vermiculite insulation contaminated with Libby amphibole asbestos. Before remodeling, fill out a Property Evaluation Notification form or call the Lincoln County Asbestos Resource Program at (406) 291-5335 for the record of EPA work at the property. The City asks owners outside its limits to make the same call.

Floodplain basements: in the floodplain a basement is any enclosed area with its floor below ground level on all sides; walk-out and daylight basements are treated differently because one side is at grade.

Zoning: the only zoning item on the Planning fee schedule is the creation of a new zoning district, at $1,800.

Libby codes and exemptions: the City’s page lists the 2021 International Residential Code as adopted. The State moved to the 2024 edition on September 26, 2026; Libby’s Municipal Code has the City Council adopt the edition the State has adopted, and state rules give a certified city 90 days from the State’s notice to do so. Sheds and playhouses under 200 square feet, fences under 6 feet and retaining walls not over 4 feet are exempt, and a modular home needs a permit only for its foundation.

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 Lincoln 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
• Lincoln County Planning forms
• Lincoln County Planning Department
• Lincoln County Planning fee schedule page
• Planning Department Fee Schedule, effective April 1, 2024 (PDF)
• Lincoln County Planning contact and office hours
• Lincoln County lakeshore construction
• Building in a floodplain in Lincoln County
• Lincoln County Health Department wastewater systems
• Lincoln County wastewater fee schedule, April 10, 2026 (PDF)
• Montana electrical permits
• City of Libby Building Inspector
• City of Libby Planning and Zoning (zoning map and ordinance)
• Libby Municipal Code
• City of Troy City Hall
• City of Troy code of ordinances
• Town of Eureka contact page

Lincoln County permit FAQs

Do I need a building permit in Lincoln County?

For a house with fewer than five units, only if it is inside Libby or Troy. Commercial buildings and residential buildings of five or more units need a State building permit wherever they are in the county.

Does Lincoln County have a building department?

No. The Planning Department handles subdivisions, floodplain and lakeshore permits and buildings for lease or rent, and the State Building Codes Program is the building-code authority, apart from residential permits inside Libby and Troy.

How much is a floodplain or lakeshore permit?

$250 to $750 under the fee schedule effective April 1, 2024. Staff set the figure during the sufficiency review, and an after-the-fact permit costs $500 to $1,500.

How much is a building permit in Libby?

The City says approximately 1% of the total construction value. Work started without a permit is charged an extra 50% of the combined fee, between $250 and $1,000.

Who issues septic permits in Lincoln County?

The Lincoln County Health Department, (406) 283-2442. A permit for a new or replacement system that already has DEQ approval is $200.

Can a homeowner install their own septic system?

Only a gravity system for their own residence on their own property; the homeowner fee is $250 and includes the first site visit. Other systems need a County-licensed installer.

Do I need a permit for a shed or fence in Libby?

Not for a shed or playhouse under 200 square feet or a fence under 6 feet tall.

Simplify Lincoln 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.

This guide is provided by Alliance Permitting for general information about Lincoln County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.