Carbon County, Montana Building Permit Guide

Carbon County does not issue building permits. A new home outside the towns needs a Group 1 Development Permit from County Planning & Development ($50, issued within 30 days of a complete application), and the same online package handles the address, county road approach and septic applications. Red Lodge is the only state-certified building jurisdiction in the county; elsewhere the Montana Building Codes Program permits commercial buildings and houses with fewer than 5 units need no building permit.

What needs a permit in Carbon County?

Carbon County has no formal zoning outside its cities and towns, but its Development Regulations, last revised in February 2024, require a County permit for most new land uses.

The building code is a separate question. Only Red Lodge enforces it locally. In the rest of the county the State requires a building permit for commercial buildings and residential buildings of 5 or more units, and none for smaller homes, farm and ranch buildings or private garages.

Who issues permits in Carbon County?

The 5 incorporated places are covered like this:

• Red Lodge (population 2,723): the City’s Building Division issues building permits inside city limits. Brian Hanna is the Building Inspector (406-446-1606 ext. 8), at City Hall, 1 South Platt. The City asks applicants to call for an appointment to submit. Its Building Division page lists the 2021 International Codes, adopted in 2022; the State’s 2024 editions took effect on September 26, 2026, and state rules give a certified city 90 days from the State’s notice to adopt them. The certification covers building only, so electrical, plumbing and mechanical permits are state permits. Work in the mapped flood hazard area also needs the City’s floodplain permit, and the Planning and Zoning Division issues sign permits.
• Bridger (population 709): not certified. The Town requires a zoning permit for new construction, filed with the Town Clerk at 108 S. D Street (406-662-3677). The zoning application fee is $50 under Resolution 254 (September 6, 2022), which notes that electrical and plumbing permits are issued by the State.
• Joliet (population 613): not certified. The Town Code requires a zoning permit for any construction, reconstruction, addition or relocation of a structure, a change of land use, a fence or a permanent sign; interior work that does not enlarge a structure is exempt. The Town Council decides applications after the zoning commission’s recommendation, and a permit lapses if the work is not finished within 1 year. The code leaves the fee to a Council resolution, and a separate title requires a floodplain permit in the flood hazard area. Town Hall is at 116 S. Main Street (406-962-3567), open Monday to Thursday, 8:00 a.m. to 4:00 p.m.
• Fromberg (population 422): not certified. Town Ordinance 250 (Title 10 of the Town Code) provides for zoning permits for new construction, additions to existing buildings and the moving of buildings or structures, and sets a 15-foot setback from the property line for a building’s street wall. Town Hall is at 118 West River Street (406-668-7383).
• Bearcreek (population 106): not certified, but the Town Code (Title 8, section 8-9-4) requires a zoning permit from the Town’s zoning administrator before a building or other structure is erected, placed, moved, expanded or structurally altered, or land is put to use. The application needs plans drawn to scale, a certificate of survey and a receipt showing that the town water and sewer connection fees are paid. The posted code sets the fee at $50 for single-family residential work and $100 for anything else (Ordinance 02-02 of 2002), and a permit stays in effect for 1 year from approval. The Town says it has newer ordinances that the Clerk can supply, and it posts a floodplain ordinance of its own. The town office is at 143 Main Street (406-446-3129).

One online application for the County permits

Planning & Development runs an online Development Permit application and payment portal. A single package form covers 6 applications, and the County says they can all be submitted at the same time:

• Group 1 residential Development Permit
• Group 2 commercial, industrial or multi-family Development Permit
• Conditional Use Permit
• Rural address
• County road approach permit
• Onsite wastewater (septic) permit

The County also posts flowcharts for residential, commercial and industrial development that link each step to its application. Other forms sit with the office concerned: a printable address application at GIS & Addressing, road cut and road encroachment permit forms at Road & Bridge, and the State’s Joint Application plus an emergency notification form at Floodplain Administration.

State building and trade permits are separate filings with the Montana Building Codes Program.

Carbon County fees (Resolution 2026-12)

The County Commissioners adopted the current fee schedule by Resolution 2026-12 on May 28, 2026, replacing the schedule adopted earlier in the year. Several permits carry a higher fee when they are applied for after the work is done.

A home on a new county road approach therefore pays $50 for the Development Permit, $40 for the address and $100 for the approach, $190 in all, before septic fees. An encroachment permit starts at $100 for the first 100 feet. A second septic site visit is a $100 re-inspection fee, and extending a septic construction authorization costs $100. The septic sheet adds $240 to the base fee where a state Certificate of Subdivision Approval issued after December 22, 2023 calls for a pressure-dosed system.

Red Lodge fees: the City charges building permit fees by project cost under its Community Development fee schedule, Resolution 3430 of March 28, 2017: $157 on a $10,000 project and $1,027 on a $100,000 one, then $7 for each further $1,000 up to $500,000. Plan review is $50 per hour with a $100 minimum, and the fee doubles when work that needed a building permit was done without one. The Council amended that resolution on June 27, 2023 and October 8, 2024, each time describing the Building Division fees as the same ones charged in 2015 and 2016; the 2024 schedule lists a $50 floodplain permit and sign permits at $10 (temporary) and $40 (permanent).

The County’s Development Process Guide dates from April 2023 and still shows $150 for a Group 2 permit and $50 for a floodplain permit; the 2026 resolution is the adopted schedule.

Electrical, plumbing and mechanical permits

No city or town in Carbon County is certified to permit the trades. Red Lodge’s own building permit application says separate permits are required for electrical, plumbing, heating, ventilation and air conditioning, and Bridger’s fee resolution describes electrical and plumbing permits as state issued. Apply to the Montana Building Codes Program for all 3 trades, wherever the property is in the county.

What the County applications ask for

Parcels without state sanitary approval have a separate County checklist, and Environmental Health asks engineers to call before digging a soil test pit so it can say whether groundwater monitoring will be needed.

How to apply: Carbon County steps

Review times and inspections

The Development Regulations give the Planning Director 30 days from a complete application to issue a Group 1 permit. A Group 2 permit goes to the Zoning Commission, which is the County Planning Board, for a decision within 60 days, after notice to owners within 500 feet. The County’s other published review periods:

• Septic: Environmental Health asks for 45 days to review an application and mail the construction authorization, and says the whole approval can take from a month to a year or more on a complex parcel. Approval runs in 3 stages: construction authorization, inspection of the installed system, and the Permit to Operate. The other County approvals have to be in place before the authorization is issued.
• Address: about 1 to 2 weeks.
• Road approach: allow 30 days.
• Floodplain permit: about 60 days from a complete application, issued after the other agencies’ permits.
• Sage grouse consultation: 45 to 60 days at the state program.

The County does not inspect buildings. In Red Lodge the Building Department needs 5 working days to review an application and plans and 24 hours’ notice before each inspection, and it inspects the foundation, the slab or under-floor work, framing, lath or gypsum board, and the finished building.

Local rules worth knowing

Setbacks: County buildings and structures must sit 10 feet from a side lot line, 20 feet from the rear lot line and 30 feet from the front lot line, street right-of-way or easement, and nothing may be built in the floodway.

Roads: approaches onto state or federal highways are approved by the Montana Department of Transportation, not the County. Approach, road cut and encroachment applications for commercial sites, or for work done by a commercial contractor, must include proof of liability and workers’ compensation insurance of at least $1,000,000 per occurrence.

Floodplain: the Floodplain Administrator is a contractor based at the Carbon Conservation District in Joliet, not at the courthouse.

Addresses: the County’s addressing standards (Resolution 2026-14, June 23, 2026) cover unincorporated areas. Inside Red Lodge, addresses come from Red Lodge Fire Rescue (406-446-2320).

Red Lodge design loads: the City’s design criteria list a 106 psf ground snow load, a minimum 70 psf design roof snow load, a 42-inch frost depth and 2 rows of ice and water shield on every roof. Contractors need a City business registration before a permit is issued.

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 Carbon 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
• Carbon County Environmental Health: septic permits, forms and installer list
• Carbon County Planning & Development
• Carbon County online Development Permit package application
• Carbon County fee schedule, Resolution 2026-12
• Carbon County Development Regulations (revised February 2024)
• Carbon County Development Process Guide (April 2023)
• Carbon County Floodplain Administration
• Carbon County GIS & Addressing
• Carbon County Road & Bridge permits
• City of Red Lodge Building Division
• Town of Bridger zoning permit forms
• Town of Bearcreek ordinances: Town Code and zoning regulations (Title 8)
• City of Red Lodge Community Development fee schedule, Resolution 3430 (2017)

Carbon County permit FAQs

Does Carbon County require a building permit for a house?

No building permit, but a new home outside the towns needs a Group 1 Development Permit from County Planning & Development, which costs $50. Inside Red Lodge the City issues building permits.

How much does it cost to permit a new home site in Carbon County?

$50 for the Development Permit, $40 for the address and $100 for a residential approach onto a county road, plus septic fees that start at a $200 base fee, with lot and system review fees added.

Do I need a permit for a barn, shop or shed?

Agricultural structures need no development permit, and neither does an accessory structure that meets the setbacks: 10 feet at the side, 20 feet at the rear and 30 feet at the front.

How long does a Carbon County Development Permit take?

Up to 30 days from a complete application for a residential Group 1 permit and up to 60 days for a Group 2 permit, which the Zoning Commission decides.

How long does septic approval take?

Environmental Health asks for 45 days to review a septic application, and says the whole approval can take from a month to a year or more depending on the parcel.

Do I need a permit to build in Bearcreek?

Yes. The Town Code requires a zoning permit from the Town’s zoning administrator before a building is erected, placed, moved, expanded or structurally altered. The posted fee is $50 for single-family residential work and $100 for other work, and the permit lasts 1 year. Call the town office on 406-446-3129.

Who issues building permits in Red Lodge?

The City of Red Lodge Building Division, 406-446-1606 ext. 8. The fee follows the City’s project-cost table, $1,027 on a $100,000 project, and trade permits there still come from the State.

Where is the Carbon County planning office?

In the County Administration Building, 17 West 11th Street, Red Lodge. The planner is a contractor who meets by appointment; call 406-690-1933.

Simplify Carbon 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 Carbon County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.