Bolthole Index

Lewis and Clark County, Montana

Zoning, building permits and septic rules in Helena, Montana

The City of Helena, Montana administers its own zoning under Title 11 of the city code1 and issues its own building permits through the Building Division2. Any building occupied inside Helena city limits must connect to city water and sanitary sewer3, so septic permits mainly matter outside the city, where Lewis and Clark Public Health issues them4.

At a glance

Building permit
Issued by the City of Helena Building Division inside city limits25
Zoning
City of Helena Title 11 Zoning, with districts such as OSR, R-1/R-2 and R-316
Water and sewer
City water and sanitary sewer required for any occupied structure3
Septic
Not an option for occupied structures inside city limits; county septic permits cover unsewered land outside the city78
Inspections
Required before work is covered up; certificate of occupancy required910
Height in R-1/R-2
30 ft maximum11
Lot coverage in R-1/R-2
40% maximum12

Who to call

Building permits

City of Helena Building Division

Building permits, plan review and inspections inside Helena city limits

406-447-8438

316 N. Park Avenue, Room 435 Helena, MT 59623

Online permits →

Planning & zoning

City of Helena Community Development Department, Planning Division

Zoning, land use and development questions inside Helena city limits

406-447-8490

316 North Park Ave, Room 445 Helena MT 59623

Online permits →

Septic permits

Lewis and Clark Public Health - Environmental Services Division

Site evaluations and septic permits for Lewis and Clark County parcels not connected to a municipal sewer

406-457-8900

Murray Building, 1930 Ninth Avenue, Helena, MT 59601

Contact details are copied from each office’s official page and were checked against it on October 23, 2026.

Off-grid gear

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

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Do you need a building permit in Helena, Montana?

Building permits inside Helena city limits come from the city, not the county or the state. The City of Helena's Community Development Department has a building division that "issues building permits, and provides inspection services at construction sites within the city limits"13, and Montana's state building-code agency lists Helena as a certified jurisdiction limited to city limits5. Applications run through the city's Civic Access online portal2.

Helena's code adopts the state-adopted International Building Code by reference, along with companion codes for residential, energy, plumbing, electrical and mechanical work14. Permit fees are set by city commission resolution rather than in the code, and we could not locate the fee schedule, so ask the Building Division for the current amounts15.

Who issues building permits in Helena, and how do you reach them?

The Helena Building Division handles building permit applications, plan review and inspections inside the city: call 406-447-8438 or visit Room 435 at 316 N. Park Avenue2. For zoning and land-use questions, the Planning Division in the same Community Development Department answers, at 406-447-849013.

The city's code lets the building official require electronic submission and require plans and specifications15. Once work starts, all work needing a permit must be inspected before it is covered up9, and no building may be occupied, even in part, until the building official issues a certificate of occupancy10.

Does Helena have zoning, and what does it mean for lot size, height and setbacks?

Helena administers its own Title 11 Zoning, covering land uses, district dimensional standards, variances, nonconforming uses, RV parks, mobile home parks and signs1. Districts include OSR, R-U, R-1/R-2, R-3, R-4/R-o, several business districts, downtown and industrial districts6. Dimensional rules differ by district, so check your parcel's district with the Planning Division before you buy.

In the main R-1/R-2 residential district, buildings may reach 30 feet11 and lot coverage is capped at 40%12; the table shows no minimum lot size for that district16. In the rural-residential OSR district, lots run 1 to 3 acres, with no more than 1 dwelling unit per acre for cluster development17, and buildings top out at 24 feet18. Dividing land inside the city is governed by Title 12, the city's subdivision regulations19.

How do septic permits work inside Helena?

Inside Helena city limits, an occupied structure must be served by city water and sanitary sewer, so a private septic system is not a route for a new home on a city lot7. Where no city main sits next to the lot, the owner extends the main at the owner's expense3.

Septic permits become relevant on land outside the city. Lewis and Clark Public Health's Environmental Services Division requires a septic permit for any residential or commercial structure that is not connected to a municipal sewer system20, and the permit must be in hand before any construction on the parcel, including drilling the well or digging the foundation20. We could not confirm how private wells are handled inside the city; ask the Building Division or Lewis and Clark Public Health.

Can you live in an RV or tiny home in Helena?

We could not confirm Helena's rules for living in an RV or a tiny home on a city lot. Title 11 includes RV parks and mobile home parks as regulated uses1, but we did not find a rule on temporary camping or tiny homes on private lots. Because every occupied structure in the city must connect to water and sewer3, expect any dwelling, however small, to be tested against those connection and building-code rules. Ask the Planning Division at 406-447-8490 before you buy a lot with a tiny home in mind13.

Building a home in Helena: the steps, in order

  1. Confirm the lot's zoning district with the Planning Division, including height, lot coverage and setbacks13.
  2. Confirm city water and sewer mains reach the lot; if not, budget to extend them3.
  3. Apply for a building permit through the city's Civic Access portal and submit plans if the building official requires them15.
  4. Schedule inspections; keep the work uncovered until the building official approves it9.
  5. Obtain a certificate of occupancy before anyone moves in10.

What stays with Lewis and Clark County, and what to check before you buy

The city's rules stop at city limits. For land outside Helena, see the Lewis and Clark County page: the county, not the city, handles septic permits4 and reviews land divisions21. County-level figures follow: Lewis and Clark County's effective property tax rate is 0.8%22.

If the lot fronts a state highway, a driveway approach needs either an approach permit or a right-of-way agreement from the Montana Department of Transportation23. New development in a mapped flood hazard area needs a permit from the local floodplain administrator24; we could not confirm how Helena handles floodplain permits, so ask the Building Division.

Watch-outs

  • Helena's published code cites an earlier edition of the International Building Code, and the city may be moving to newer editions, so ask the Building Division which edition governs your permit14.
  • We could not confirm Helena's building permit fees, owner-builder rules, short-term rental rules or driveway permit rules; ask the Building Division at 406-447-84382.
  • Septic permits and wells outside city limits go through Lewis and Clark Public Health, and construction on an unsewered parcel cannot start before the septic permit is issued20.

Sources

  1. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  2. City of Helena Building Division (helenamt.gov)
  3. 3-1-10: Certificate of occupancy (Title 3, Chapter 1 Administration) (Helena), quoted and re-checked
  4. Septic System Programs, quoted and re-checked
  5. Certified City, County and Town Programs, quoted and re-checked
  6. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  7. 3-1-10: Certificate of occupancy (Title 3, Chapter 1 Administration) (Helena), quoted and re-checked
  8. Septic System Programs, quoted and re-checked
  9. codelibrary.amlegal.com (Helena), quoted and re-checked
  10. 3-1-10: Certificate of occupancy (Title 3, Chapter 1 Administration) (Helena), quoted and re-checked
  11. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  12. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  13. City of Helena Community Development Department, Planning Division (helenamt.gov)
  14. 3-2-1: Building code (Title 3, Chapter 2) (Helena), quoted and re-checked
  15. 3-1-10: Certificate of occupancy (Title 3, Chapter 1 Administration) (Helena), quoted and re-checked
  16. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  17. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  18. 11-4-2: Lot requirements for zoning districts (Title 11 Zoning, Chapter 4) (Helena), quoted and re-checked
  19. Helena, MT Code of Ordinances (American Legal Publishing) - overview (Helena), quoted and re-checked
  20. Lewis and Clark Public Health - Environmental Services Division (lccountymt.gov)
  21. Subdivision Review, quoted and re-checked
  22. Effective property tax rate: Bolthole Index county data
  23. Approach Manual for Landowners and Developers (Montana statewide rule), quoted and re-checked
  24. Stream Permitting (Montana statewide rule), quoted and re-checked

Written October 23, 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 Helena

Helena’s own rules

  • Building code adoptedAdopted

    New construction, alteration and repair inside Helena city limits: the City adopts the state-adopted International Building Code by reference.

    • Adopts the current IBC as adopted by the state of Montana, with Appendix C (Group U agricultural buildings), amendments and modifications in ARM Title 24, chapter 301.
    • Same adoption-by-reference structure in 3-2-2 (residential code), 3-2-3 (energy), 3-2-4 (existing building), 3-2-5 (plumbing), 3-2-6 (electrical), 3-2-7 (mechanical), 3-2-8 (fuel gas) and 3-2-9 (swimming pool and spa) per the chapter 2 heading; those sections were not opened.
    • The 3-2-1 text cites ord. 3301 (9-26-2022) as the last amendment.
    • Conflict to verify: the City Codes & Design Requirements page (search snippet, not opened) reportedly says 2024 IBC/IRC/IMC/IFGC/IEBC/UPC and 2023 NEC enforcement begins October 26, 2026 while its body says effective October 26, 2024. Confirm which edition governs with the Building Division.
    “the city of helena hereby adopts and by this reference incorporates into this title as if set forth in full, except any regulations which are not applicable to local government jurisdictions, the current edition of the international building code”
  • InspectionsRequired

    Permitted work inside Helena city limits

    • Inspections are required at the stages set by the City to assure compliance with the enforced codes; the permit holder must correct unsafe or noncompliant conditions found on inspection (3-1-9(c)).
    “all work requiring a permit must be inspected by the building official at various intervals, as required by the city, to assure compliance with the enforced codes. no work may be covered up until the same has been approved by the building official.”
  • Certificate of occupancyRequired

    Any building occupied, in whole or in part, inside Helena city limits

    • A temporary certificate of occupancy may be issued for use of a portion of a building before the whole building is complete (3-1-10(d)).
    • An issued certificate is not a guarantee of total code compliance (3-1-10(c)).
    “no building may be occupied, including in part, unless or until a certificate of occupancy has been issued by the building official.”
  • Local zoningPresent

    Land inside Helena city limits: the City of Helena administers its own Title 11 Zoning (land uses, district dimensional standards, variances, nonconforming uses, RV parks, mobile home parks, downtown and transitional districts, signs, landscaping, PUDs).

    • Chapter 4 district dimensional standards apply to every lot in a zoning district inside city limits; lots existing at the effective date may not be reduced below the standards.
    “title 11 zoning chapter 1 administration and enforcement chapter 2 land uses chapter 3 conditional uses chapter 4 district dimensional standards”
  • Zoning districtsPublished

    Zoning districts inside Helena city limits

    • Districts include OSR, R-U, R-1/R-2, R-3, R-4/R-o, B-1, B-2, B-3, DT, TR, CLM, M-I, PLI and airport (11-4-2 Table 2).
    “table 2 lot requirements by zoning district du = dwelling unit osr (open space/ residential) r-u (residential- urban) r-1/r-2 (residential) r-3 (residential) r-4/r-o (residential- office)”
  • Minimum lot sizeSpecified

    Lots in the OSR (open space/residential) district inside Helena city limits (rural-residential district)

    • Cluster development: no more than 1 dwelling unit per acre, referring to section 11-2-5 of title 11 (not opened).

    lot area: 1-3 acres (cluster development limit cross-referenced to 11-2-5)

    “lot area 1 - 3 acres; no more than 1 du per acre for cluster development.”
    One more reviewed finding on this topic
  • Lot coverageSpecified

    Lot coverage in the R-1/R-2 (residential) district inside Helena city limits (main single-family district)

    • Lot coverage counts all buildings and structures; it excludes the first two feet of roof eaves, uncovered decks, fences, walls and pools (11-4-1 definition).
    • 11-4-2(a): lot coverage may not exceed the limit of the district.

    lot coverage: <= 40 percent (maximum)

    “lot coverage no maximum 60% maximum additional 5% for porch attached to front or side 40% maximum 40% maximum 60% maximum”
    One more reviewed finding on this topic
  • Building heightSpecified

    Buildings in the R-1/R-2 (residential) district inside Helena city limits (main single-family district)

    • Spires, belfries, cupolas, chimneys, water tanks, elevator housings, solar energy systems, streetlights and utility poles are exempt from district height limits (11-4-2(c)(1)).
    • A building may not exceed the district height limit except by variance (11-4-2(c)(2)).
    • Height is measured from the reference datum defined in 11-4-1.

    building height: <= 30 ft (maximum)

    “height 24' maximum 42' maximum 30' maximum 36' maximum 42' maximum”
    One more reviewed finding on this topic
  • Off-grid sanitationProhibited

    Occupying a structure inside Helena city limits without city water and city sanitary sewer service

    • Applies to occupancy; the owner-extension duties in 3-1-5(c)-(d) apply where no adjacent city main exists.
    “no structure may be occupied unless it is served by city water and sanitary sewer services.”
  • Mandatory utility hookupWater and sewer (with conditions)

    Any structure to be occupied inside Helena city limits must be served by city water and city sanitary sewer

    • Connections must be made to a city water or sanitary sewer main in the right-of-way, alley or city utility easement adjacent to the structure, in compliance with title 6 and city engineering standards (3-1-5(b)).
    • If no city water main is adjacent, the owner must extend the main at the owner's expense through the entire length of the property served (3-1-5(c)); the same applies to sewer, with length set by the public works director (3-1-5(d)).
    • Title 6 rule 16 states all wastewater service must be provided from public mains (6-3-6).
    “no structure may be occupied unless it is served by city water and sanitary sewer services.”
  • Subdividing landRegulated (with conditions)

    Division of land inside Helena city limits

    • Subdivisions are governed by Title 12 Subdivision Regulations of the city code; the title's requirements were not opened.
    “title 11 zoning title 12 subdivision regulations title 13 fire regulations”
  • Permit processPartial

    Building permit application process inside Helena city limits

    • Building official may require electronic submission of permit applications (3-1-7(a)).
    • Plans and specifications are required when the building official requires them (3-1-8).
    • Inspections and certificate of occupancy follow (3-1-9, 3-1-10); decisions may be appealed in writing to the building official (3-1-11).
    “the property owner, or the owner's designee, must submit the information for each permit as required by the building official, on the forms provided.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Helena or Lewis and Clark County directly.

  • Owner-builder exemption — Owner-builder construction inside Helena city limits
  • Minimum dwelling size — Minimum floor area of a dwelling inside Helena city limits
  • Camping on your land — Temporary tent or camping use on private land inside Helena city limits
  • Tiny homes — Tiny home used as a dwelling inside Helena city limits
  • Who permits septic — On-site wastewater (septic) inside Helena city limits
8 more unanswered
  • Septic permit
  • Septic inspection
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees

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 Helena publishes no rule on the point, not that none exists. Lewis and Clark County’s page lists the county offices to call.

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