Bolthole Index

Lincoln County, Montana

Building permits, zoning and land rules in Troy, Montana

Troy, Montana requires a city building permit for construction and changes of building use inside city limits, with exemptions for certain small projects.1 Lincoln County Health Department handles non-public septic systems inside Troy, and a local wastewater permit is required before installation.23 We could not confirm Troy’s general zoning rules; ask City Hall about the proposed use before buying.4

At a glance

Building permit
City-issued building permit required, with small-project exemptions1
Zoning
General zoning rules unconfirmed; ask Troy City Hall4
Septic permit
Local wastewater permit required before installation; county Environmental Health handles non-public systems32
Inspections
Permit holder must notify the city building official when work is ready5
Move-in approval
Certificate of occupancy required before the building can be used6
Building permit fees
Published schedule based on project valuation; confirm the current fee with the building inspector7
Well water rights
Small groundwater developments may qualify for a state permit exception; prior Notice of Intent required beginning in 20268

Who to call

Building permits

City of Troy Building Inspector

City building permit applications, plan review and construction inspections

406-295-9851

[email protected]

301 E. Kootenai Avenue, Troy

Online permits →

Planning & zoning

Troy City Hall

Starting contact for unresolved city land-use questions

406-295-4151

[email protected]

301 E Kootenai Ave

Septic permits

Lincoln County Health Department, Environmental Health

Non-public wastewater permits and referral to Environmental Health for site evaluations

283-2442

Online permits →

Contact details are copied from each office’s official page and were checked against it on October 11, 2026.

Off-grid gear

Going off-grid in Troy means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Troy, MT?

Troy requires a city-issued building permit for construction, additions, alterations, repairs, demolition and changes of building use inside city limits.1 Troy’s exemptions include fences under 6 feet, playhouses or storage sheds under 120 square feet, residential re-siding and cosmetic finish work.1 Separate state electrical, plumbing and mechanical permits may also be required for a Troy project.1 Do not start a permitted project until the city building permit is issued and the fees are paid.6

Who issues building permits in Troy, and how do you apply?

Troy’s building official reviews the city building permit application and plans; applications are available at City Hall or from the building inspector.9 Contact the City of Troy Building Inspector at 406-295-9851 or [email protected], and return the application and required plans to the building official or City Hall at 301 E. Kootenai Avenue, Troy.10 Typical Troy application drawings include a site plan, floor plans and a section view, with additional information possible for commercial, multifamily or unusual structures.9 Troy publishes valuation-based building permit fees; ask the inspector to confirm the current charge for the proposed project.7

Does Troy have zoning, and can you live in an RV or tiny home?

We could not confirm Troy’s general zoning ordinance, district map, residential setbacks or minimum lot size; ask Troy City Hall for the rules applying to the specific parcel.4 We also could not confirm whether Troy allows residential RV occupancy, tiny-home occupancy or an accessory dwelling; describe the intended dwelling and duration of occupancy when contacting City Hall.4 Troy has adopted building codes, and changing a building’s use requires a city building permit.111 Ask the building inspector which approvals the proposed dwelling needs before buying or moving it onto the property.10

How do septic permits work inside Troy?

Lincoln County Environmental Health administers non-public wastewater systems inside Troy, including individual, shared and multi-user systems; Montana DEQ has primary responsibility for public wastewater systems.2 A local wastewater treatment system permit is required before a system is installed inside Troy.3 Site evaluations must be performed by a Qualified Site Evaluator, and system design and installation must follow DEQ’s wastewater standards.3 Lincoln County requires a licensed septic installer, except when a homeowner constructs or alters a gravity system for the homeowner’s own residence on the homeowner’s own property; that exception does not remove the wastewater permit requirement.3

Building a home in Troy: what are the steps, in order?

  1. Ask Troy City Hall to confirm the parcel’s land-use requirements and any unresolved dwelling restrictions.4
  2. If proposing septic, arrange a Qualified Site Evaluator and obtain the local wastewater permit before installation.3
  3. Submit the city building permit application with the site plan, floor plans and construction details required for the project.9
  4. After review, collect and pay for the city building permit at City Hall before construction starts.96
  5. Notify Troy’s building official when work is ready for inspection, and obtain the certificate of occupancy before using the building.56

What should you check before buying land in Troy?

Ask Troy City Hall to clarify utility availability, floodplain review and access requirements for the parcel; we could not confirm those parcel-specific answers.4 For land outside Troy city limits, use the Lincoln County guide for the county’s residential building permit answer.12 If a Troy project needs a new well, Montana groundwater developments using no more than 35 gallons per minute and 10 acre-feet annually may qualify for a water-permit exception.8 Beginning in 2026, that exception requires a Notice of Intent before water use, with a $400 filing fee; eligibility is not automatic.8

Watch-outs

  • Troy’s building permit and Lincoln County’s septic permit are separate approvals; obtaining the city building permit does not replace the required local wastewater permit.13
  • We could not confirm a general Troy owner-builder exemption, RV occupancy permission or tiny-home occupancy rule; ask City Hall and the building inspector before committing to that plan.410
  • A Troy building cannot be used until the certificate of occupancy is issued.6

Sources

  1. City of Troy Building Permit Requirements and Application (Troy), quoted and re-checked
  2. Lincoln County Health Department, Septic Permitting (Troy), quoted and re-checked
  3. Lincoln County Health Department, Septic Permitting (Troy), quoted and re-checked
  4. Troy City Hall (cityoftroymontana.com)
  5. City of Troy Building Permit Requirements and Application (Troy), quoted and re-checked
  6. City of Troy Building Permit Requirements and Application (Troy), quoted and re-checked
  7. City of Troy Building Permit Fee Schedule (Troy), quoted and re-checked
  8. Exempt Well Updates and Information (Montana statewide rule), quoted and re-checked
  9. City of Troy Building Permit Requirements and Application (Troy), quoted and re-checked
  10. City of Troy Building Inspector (cityoftroymontana.com)
  11. Troy Code § 9-1-1, Technical Codes and Regulations Adopted (Troy), quoted and re-checked
  12. Montana DLI - Certified City, County and Town Programs (2026 county census)

Written October 11, 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.

Answers from the rulebook for Troy

Troy’s own rules

  • Building permitRequired

    Construction, addition, alteration, repair, demolition, or change of use of structures inside Troy city limits.

    • Permits are not required for fences under six feet, playhouses or storage sheds under 120 square feet, painting or papering or other cosmetic finish work, residential re-siding, retaining walls under four feet, and walk, slabs or other flat work less than 30 inches above grade.
    • Separate state electrical, plumbing, and mechanical permits may also be required.

    fence exemption height: < 6 feet · storage shed exemption area: < 120 square feet · retaining wall exemption height: < 4 feet · flat work exemption height: < 30 inches above grade

    “The construction, addition, alteration, repair or demolition of any structure within the city requires a city issued general permit.”
  • Building code adoptedAdopted

    Buildings and structures inside Troy city limits.

    • The city adopts the listed model codes and state administrative regulations.
    • The code provides for issuance of permits and collection of fees and penalties.
    “The city hereby adopts the following model codes and administrative regulations:”
  • InspectionsRequired

    Permitted construction inside Troy city limits.

    • The permit holder must notify the building official when work is ready for inspection.
    • The inspection record lists foundation, concrete slab or underfloor, frame, energy conservation, gypsum board, and final inspections.
    • Final inspection occurs after the building is substantially completed and ready for occupancy.
    “REMEMBER 2009 IBC-IRC required the permit holder to notify the building official when work is ready for inspection.”
  • Certificate of occupancyRequired

    Use of a permitted building inside Troy city limits.

    • The building cannot be used before the certificate of occupancy is issued.
    • The application also states that construction may not start until fees are paid and the permit is issued.
    “A certificate of occupancy needs to be issued before the building can be used.”
  • Who permits septicMixed (with conditions)

    Wastewater systems inside Troy city limits: Lincoln County Health Department administers non-public wastewater systems, while MDEQ has primary responsibility for public wastewater systems.

    • Non-public systems include individual, shared, and multi-user systems.
    • Public systems are defined by the county page as serving more than 24 persons for more than 60 days a year or having more than 14 connections.
    “Environmental Health Services is responsible for ensuring that non-public wastewater treatment systems (individual/shared, multi-user) are permitted and installed in accordance with state and local regulations.”
  • Septic permitRequired

    Non-public or public wastewater treatment systems installed inside Troy city limits, under Lincoln County Health Department permitting.

    • A local wastewater treatment system permit is required before installation.
    • Site evaluations must be performed by a Qualified Site Evaluator.
    • Systems must be designed and installed per DEQ Circular 4.
    • A Lincoln County septic installer license is required, except for a homeowner constructing or altering a gravity system for the homeowner's own residence on the homeowner's own property.
    “A local wastewater treatment system permit is ALWAYS required before a system (non-public or public) is installed.”
  • Permit feesPublished

    City building permits inside Troy city limits.

    • The code separately states that building permit fees are established and adjusted periodically by city council resolution.
    • The published schedule is based on total valuation.

    valuation fee $1-$500: 24 USD · valuation fee $501-$2000: $24 for first $500 plus $3 for each additional $100 or fraction thereof USD (to and including $2,000) · valuation fee $2,001-$40,000: $69 for first $2,000 plus $11 for each additional $1,000 or fraction thereof USD (to and including $40,000)

    “$501 TO $2,000 $24 for the first $500; plus $3 for each additional $100 or fraction thereof, to and including $2,000”
  • Permit processPublished

    City building permit applications inside Troy city limits.

    • Applications are available at City Hall or from the building inspector.
    • Most projects require one set of drawings or plans and specifications.
    • The plans typically include a site plan, floor plans, and section view; additional information may be required for commercial, multifamily, unusual, or hazardous structures.
    • The permit can be picked up and paid for at City Hall during regular business hours after review and issuance.
    “After you submit your plans and your permit application, the building official will review your application and will issue the permit.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Troy or Lincoln County directly.

  • Owner-builder exemption — Owner-builder construction inside Troy city limits.
  • Local zoning — Land inside Troy city limits.
  • Zoning districts — Zoning districts and maps inside Troy city limits.
  • Minimum dwelling size — General residential dwellings inside Troy city limits.
  • Minimum lot size — Residential lots inside Troy city limits.
10 more unanswered
  • Setbacks
  • Lot coverage
  • Building height
  • Tiny homes
  • Accessory dwellings
  • Septic inspection
  • Well permit
  • Agricultural exemption
  • Subdividing land
  • Short-term rentals

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Troy publishes no rule on the point, not that none exists. Lincoln County’s page lists the county offices to call.

← All of Lincoln County: county rules, score and offices