Bolthole Index

Marion County, Oregon

Building permits, zoning and septic rules in St. Paul, Oregon

St. Paul, Oregon assigns building permits, land-use approval and site-plan approval to the city; Marion County handles building plan review and inspections.1 St. Paul publishes its own development code and zoning map.2 For properties without community sewer, Marion County Building Inspection handles septic under Oregon DEQ rules, with exceptions for systems reserved to DEQ.3

At a glance

Building permits
City-issued; Marion County reviews plans and inspects construction45
Zoning
City development code and zoning map; city land-use and site-plan approval21
Septic
Marion County Building Inspection, under DEQ rules; community-sewer properties excepted3
RV living
Local residential occupancy rule unconfirmed; ask City Administration6
Tiny homes
Local occupancy and land-use treatment unconfirmed; ask City Administration6
Owner-builder
Limited state exemption for ceiling heights, room sizes and temperature requirements; building permit still required7

Who to call

Building permits

City of St. Paul — City Administration

City contact for building applications, zoning, land-use and site-plan approval; county plan review and inspections remain separate.

503-633-4971

[email protected]

Building permits

Marion County Building Inspection

Building plan review and inspections for St. Paul; city building permits and land-use approval are separate.

503-588-5147

[email protected]

Online permits →

Septic permits

Marion County Building Inspection - Onsite Sewage Disposal Program

Septic (onsite sewage disposal) site evaluations, construction/installation permits, alterations, repairs and inspections for Marion County, as DEQ's contract agent

503-588-5147

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 St. Paul means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in St. Paul, OR?

St. Paul assigns the building permit for construction inside city limits to the city, while Marion County performs plan review and inspections.4 City land-use approval and site-plan approval are separate parts of the building workflow.1 Start with City Administration and the building permit application published on the city website; ask which approvals your proposed work needs before submitting plans.6 Do not treat the county review role as a substitute for city building-permit approval.4

Who handles St. Paul building applications and inspections?

City Administration is the starting contact for the building permit application and the city development code and zoning map.6 St. Paul assigns land-use approval, site-plan approval and driveway approval to the city; Marion County handles building plan review, fire-and-life-safety plan review, master-plan approval and inspections.1 Use the county Building Inspection contact for the county portion of that workflow.8 Septic is a separate county program, including inside St. Paul when community sewer does not serve the property.3

Does St. Paul have zoning, lot-size and setback rules?

St. Paul publishes a city development code and zoning map, and the city handles land-use and site-plan approvals inside city limits.21 Ask City Administration to identify the parcel’s district and confirm the applicable lot size, setbacks, lot coverage and height before choosing a house footprint; we could not confirm those district-specific requirements here.6 For land outside city limits, use the Marion County guide: Marion County Planning administers land-use regulation in unincorporated areas, rather than St. Paul’s city zoning.9

How do septic permits work inside St. Paul?

Marion County Building Inspection issues septic permits inside St. Paul for properties not served by community sewer, acting as Oregon DEQ’s contract agent; DEQ retains systems reserved under its Water Pollution Control Facilities rules.3 For an undeveloped parcel, the county directs applicants to a septic site evaluation; installation follows a valid site-evaluation approval through a construction installation application.10 Repairs, alterations and connections to an existing system require the authorization appropriate to the work.11 A composting toilet does not eliminate the need for approved wastewater treatment for other household water under Oregon rules.12

Can you live in an RV or tiny home in St. Paul?

We could not confirm St. Paul’s local rule for residential RV occupancy, temporary camping or tiny-home occupancy; ask City Administration about the proposed use and parcel before buying a vehicle or building a tiny home.6 Oregon’s private-land camping-vehicle provision requires landowner consent, adequate area for safe approved water and sewage facilities, and compliance with applicable state and local installation standards.13 Those conditions do not establish St. Paul’s local occupancy answer.13 For an owner-built residence, Oregon’s limited exemption concerns ceiling heights, room sizes and temperature requirements, and still requires a building permit.7

Building a home in St. Paul: what steps come first?

  1. Ask City Administration to identify the parcel’s zoning and discuss the proposed home using the city development code and zoning map.6
  2. Resolve city land-use and site-plan approval and ask how to submit the city building permit application for county plan review.16
  3. Confirm sewer service with the city; if the parcel needs septic, arrange the county site evaluation before the septic construction installation application.310
  4. Coordinate building inspections with Marion County and septic inspections with the county onsite program when applicable.514

We could not confirm city sewer-connection thresholds, current building-permit fees or floodplain-development requirements; ask City Administration to resolve those parcel-specific questions before committing to a design.6

Watch-outs

  • St. Paul building permits and land-use approval belong to the city, while Marion County performs plan review and inspections; contact both for their respective work.1
  • We could not confirm local RV or tiny-home occupancy rules in St. Paul; ask City Administration before planning to live on the lot while building.6
  • The city’s building-permit role does not transfer septic administration: Marion County handles onsite sewage under DEQ rules for properties without community sewer, except DEQ-reserved systems.3

Sources

  1. Where to Apply for Permits (St. Paul), quoted and re-checked
  2. cityofstpaul.us (St. Paul), quoted and re-checked
  3. Onsite Sewage Disposal Program (Septic) (St. Paul), quoted and re-checked
  4. Where to Apply for Permits (St. Paul), quoted and re-checked
  5. Where to Apply for Permits (St. Paul), quoted and re-checked
  6. City of St. Paul — City Administration (cityofstpaul.us)
  7. 2023 Oregon Residential Specialty Code - ORS 455.320 reprinted (Oregon statewide rule), quoted and re-checked
  8. Marion County Building Inspection (co.marion.or.us)
  9. Planning & Zoning (2026 county census)
  10. Marion County Building Inspection - Onsite Sewage Disposal Program (co.marion.or.us)
  11. Onsite Sewage Disposal Program (Septic) (St. Paul), quoted and re-checked
  12. What do I do with the finished material? (Oregon statewide rule), quoted and re-checked
  13. Oregon Revised Statutes, ORS 446.125 Occupancy on private land (Oregon statewide rule), quoted and re-checked
  14. Where to Apply for Permits (St. Paul), quoted and re-checked

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 St. Paul

St. Paul’s own rules

  • Building permitRequired

    Building permits for construction inside St. Paul city.

    • The official Marion County responsibility table assigns the permit to the City of St. Paul.
    • Marion County performs plan review and inspections for the listed building permit workflow.
    • Land-use approval and site-plan approval are assigned to the city.
    • Other permit types may have separate responsibility assignments.
    “City of St. Paul [...] BUILDING | City | County | Other [...] Permit | X |   |”
  • InspectionsRequired

    Building inspections for construction inside St. Paul city.

    • The City of St. Paul responsibility table assigns inspections to Marion County.
    • The city remains responsible for land-use and site-plan approvals.
    “City of St. Paul [...] BUILDING | City | County | Other [...] Inspections |   | X |”
  • Local zoningPresent

    Land inside St. Paul city limits.

    • The city publishes a development code and zoning map on its official website.
    “St. paul development code [...] St. Paul Zoning Map”
  • Zoning districtsPublished

    Zoning districts and zoning geography inside St. Paul city.

    • The official city Public Works page links to a St. Paul Zoning Map.
    • The underlying map PDF was not accessible through the permitted webpage-opening tool, so district names and dimensional schedules were not extracted.
    “St. Paul Zoning Map St. Paul was awarded “Outstanding Performer” for our dedication to the water quality in this city.”
  • Permit processPartial

    Building-permit process inside St. Paul city.

    • The city is responsible for land-use approval, permits, site-plan approval, and driveway approval in the official responsibility table.
    • Marion County is responsible for plan review, fire-and-life-safety plan review, master-plan approval, and inspections.
    • The city official site publishes a building permit application link.
    “Land Use Approval | X |   | [...] Permit | X |   | [...] Plan Review |   | X | [...] Site Plan Approval | X |   | [...] Inspections |   | X |”

Rules another office applies inside St. Paul

St. Paul does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

  • Building code adoptedAdopted (with conditions)

    Construction, reconstruction, and repair of one- and two-family dwellings and townhouses inside St. Paul city.

    • The Oregon Residential Specialty Code applies to the listed residential building types.
    • The 2026 ORSC administrative provisions became effective and mandatory October 1, 2026.
    • The 2026 ORSC construction provisions are effective October 1, 2026 with a six-month phase-in period and become mandatory April 1, 2027.
    • During the phase-in period, except for Chapter 1, use of the 2023 ORSC or 2026 ORSC is permitted.

    administrative provisions effective date: 2026-10-01 · construction provisions mandatory date: 2027-04-01

    “The division works with building officials, technical committees, advisory boards, and the public to adopt, amend, and interpret the Oregon Residential Specialty Code (ORSC). This code applies to the construction, reconstruction, and repair of one- and two-family dwellings and townhouses. [...] Administrative provisions (Chapter 1): [...] Effective and mandatory Oct. 1, 2026 [...] Construction provisions (Chapters 2 - 44 and appendices): [...] Effective Oct. 1, 2026 with six-month phase-in period [...] Mandatory April 1, 2027 [...] During the phase-in period, except for Chapter 1, use of the 2023 ORSC or the 2026 ORSC is permitted.”
  • Who permits septicMixed (with conditions)

    Onsite sewage systems inside St. Paul city where a property is not served by community sewer.

    • Marion County Building Inspection issues septic permits within Marion County.
    • Marion County Building Inspection is a contract agent of the Oregon Department of Environmental Quality.
    • Permits are issued under DEQ onsite sewage rules.
    • Exceptions are properties served by community sewer and systems reserved by DEQ under WPCF rules.
    “Marion County Building Inspection issues all septic system permits within Marion County. Building Inspection is a contract agent of the Oregon Department of Environmental Quality (DEQ). Therefore, septic permits are issued under DEQ's DEQ Onsite Sewage Disposal Rules. The only exceptions are properties served by a community sewer system and systems reserved by DEQ, under DEQ Water Pollution Control Facilities (WPCF) rules.”
  • Septic permitRequired

    New, altered, repaired, or evaluated onsite sewage systems inside St. Paul city.

    • A septic permit or other listed septic authorization is required according to the work type.
    • Properties served by community sewer are excepted from the onsite sewage program.
    • A plumbing accessory structure may not require a septic permit when gravity flow to the existing septic tank is attainable, but plumbing-permit requirements still apply.

    accessory-structure septic permit exception: gravity flow to existing septic tank attainable (plumbing permit requirements may still apply)

    “If repairing or replacing the septic tank, effluent line, or distribution box(es) — Apply for a Septic MINOR REPAIR. [...] If repairing or replacing the drain field, or any alternate treatment technology with or without new septic tank— Apply for a Septic MAJOR REPAIR. [...] If plumbing is proposed in the accessory structure and gravity flow to the existing septic tank is attainable - A Septic permit is not required. Check for plumbing permit requirements.”
  • Septic inspectionRequired

    Onsite sewage system installations, repairs, and alterations inside St. Paul city.

    • Marion County Building Inspection performs onsite sewage inspections for St. Paul in the official responsibility table.
    • The program does not apply to properties served by community sewer.
    • The required inspection type depends on the septic work and permit.
    “City of St. Paul [...] ONSITE SEWAGE/SEPTIC PERMITS | City | County | Other [...] Inspections |   | X |”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask St. Paul or Marion County directly.

  • Certificate of occupancy — Certificate-of-occupancy requirements for buildings inside St. Paul city.
  • Minimum dwelling size — Minimum dwelling size inside St. Paul city.
  • Minimum lot size — Minimum lot size inside St. Paul city.
  • Setbacks — Required setbacks inside St. Paul city.
  • Lot coverage — Lot-coverage limits inside St. Paul city.
14 more unanswered
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Subdividing land
  • 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 St. Paul publishes no rule on the point, not that none exists. Marion County’s page lists the county offices to call.

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