Polk County, Oregon requires a building permit for a home outside city limits, issued by Polk County Community Development, whose Building Division also covers the City of Falls City12. Unincorporated land has county zoning, reviewed through Site Plan Review before the permit issues3. Septic permits come from Polk County Environmental Health, including inside city limits and urban growth boundaries, where the city must also sign off sewer availability45.
At a glance
- Building permit
- Required in unincorporated Polk County, issued by Community Development1
- Zoning
- Yes, countywide, with Site Plan Review for setbacks and floodplain6
- Septic permits
- Polk County Environmental Health handles site evaluations, permits, and inspections7
- Owner-builder exemption
- Limited exemption; permits and inspections still apply8
- Minimum lot size
- 5 acres in AR-5; 10 acres in AR-10 and AF-109
- Setbacks (AR-5/AR-10/AF-10)
- 30 ft front, 20 ft side and rear10
- Accessory dwelling unit
- Allowed up to 900 sq ft, with different rules inside and outside urban growth boundaries1112
- RV or tiny home living
- Private-land occupancy needs adequate water, sewage, and code compliance; zoning still controls the site13
Who to call
Building permits
Polk County Community Development – Building Division
Building, mechanical, plumbing, and manufactured-structure permits for unincorporated Polk County and the City of Falls City (electrical also outside Dallas and Independence); Site Plan Review for zoning and floodplain compliance
850 Main Street, Dallas, OR 97338
Zoning
Polk County Community Development – Planning Division
Zoning determinations, land-use applications, subdivisions and partitions, and the county comprehensive plan; shares Community Development's front counter
850 Main Street, Dallas, OR 97338
Septic permits
Polk County Environmental Health – Onsite Wastewater Treatment Program
Septic site evaluations, permits, and inspections for Polk County, acting as Oregon DEQ's local contract agent
850 Main Street, Dallas, OR 97338
Roads & driveways
Right-of-way permits for driveway access, utility work, mailbox installation, and dust-control or vegetation activity on county roads outside city limits
820 SW Ash St., Dallas, OR 97338
Contact details are copied from each office’s official page and were checked against it on October 9, 2026.
Off-grid gear
Going off-grid in Polk County means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.
Do you need a building permit in Polk County, Oregon?
Yes: Polk County requires a building permit for a home in the unincorporated county, and the permit cannot be released until the required septic permit has been applied for and issued1. One- and two-family homes and townhouses within its scope must follow the Oregon Residential Specialty Code, which also governs reconstruction and repair14. Every project goes through a Site Plan Review checking use, setbacks, floodplain location, height, and nearby wetlands or other significant resources3. Oregon's owner-builder exemption is limited to structural-code requirements for ceiling height, room size, and maintaining specified temperatures; permits, fees, plan review, inspections, and core safety rules still apply8. A building permit expires if work does not start within 180 days of issuance or is suspended for 180 days or more, so ask for an extension before the deadline if needed15.
Who is the Polk County building department, and how do you reach them?
Polk County Community Development's Building Division issues residential and manufactured-structure permits outside city limits and in the City of Falls City2. Reach the Building Division at 503-623-9237 or by email, or visit the Community Development office at 850 Main Street in Dallas16. A Permit Specialist performs the Site Plan Review before permit issuance3. Residential permits typically take about 2 to 4 weeks once an application is complete; incomplete plans, other required applications, or unresolved land-use conditions can extend that timeline2. Building and manufactured-structure fees vary with project cost, construction type, and square footage, and the exact charge is determined after plan review17. A new dwelling or townhouse cannot be occupied until the building official issues a certificate of occupancy or temporary certificate18.
Does Polk County have zoning?
Yes: unincorporated Polk County has county zoning, and residential and manufactured-structure projects receive a Site Plan Review for use, setbacks, floodplain location, height, and nearby significant resources or wetlands3. Minimum lot sizes depend on the district: 5 acres in AR-5 and 10 acres in AR-10 and AF-109. Standard yards in those districts are 30 feet in front and 20 feet at the side and rear10. Height also depends on the district; the EFU and FF limits are 100 feet, with airport-overlay and conditional-approval exceptions19. Polk County allows one accessory dwelling unit on a qualifying rural lot of at least 2 acres outside an urban growth boundary, capped at 900 square feet and located within 100 feet of the existing home11. Within an urban growth boundary, one accessory dwelling may accompany a detached single-family home in specified residential zones; it is capped at 900 square feet or 75% of the main home's floor area, whichever is less, and cannot be a manufactured dwelling12.
How do septic permits work in Polk County?
Polk County Environmental Health handles onsite wastewater permitting, site evaluations, and related inspections throughout Polk County7. The office issues specifications for new systems, repairs, and alterations, provides pre-cover inspections, and may authorize an existing system when a home is replaced20. The county's published duties do not establish routine periodic inspections of every septic system20. A septic permit application needs a site evaluation approval, a plot plan, land-use approval from the Planning Division and the permit fee21. For a property inside city limits or an urban growth boundary, the city must sign off on a DEQ Land Use Compatibility Statement and a Sewer Availability Form, and both forms must accompany the application5. Call Community Development at 503-623-9237 for current septic fees22. Only about 3.5% of Polk County soils are rated free of severe limits for a conventional drain field, so make the site evaluation an early contingency and be prepared for an alternative design23. Off-grid does not mean sewage can go untreated: discharging raw or partly treated sewage onto the ground or into Oregon waters is a nuisance, and using, installing, replacing, or repairing an onsite system requires the applicable authorization or permit24. A composting toilet still requires approved wastewater treatment for the home's remaining wastewater25.
Can you live in an RV or tiny home on your land in Polk County?
Oregon allows a camping vehicle on private land with the owner's consent when the parcel has adequate approved water and sewage facilities and the occupant meets applicable sanitation, plumbing, electrical, and sewerage standards13. That state rule does not settle Polk County zoning or make an RV a permanent dwelling, so ask the Planning Division whether the proposed use is allowed on the specific parcel26. In Polk County's Timber Conservation zone, a private campground is a conditional use for temporary recreation rather than residential use, and the same camper or vehicle may stay no more than 30 days in a consecutive six-month period27. Manufactured homes have clearer district rules: a single-family mobile home is permitted in AR-5, subject to other placement, building, septic, and development standards28. In the SR zone within an adopted urban growth boundary, a manufactured dwelling needs a county placement permit, applicable building permits, a foundation system, and continuous sight-obscuring skirting before occupancy29. Polk County has not established a specific standalone tiny-home occupancy rule in the materials reviewed, so take the construction type and proposed site to Community Development before buying16.
Building a home in Polk County: what are the steps, in order?
- Confirm the parcel's zoning, allowed use, lot size, and setbacks with the Planning Division263.
- Get a septic site evaluation and permit from Polk County Environmental Health, with city sign-offs if the parcel is inside city limits or an urban growth boundary5; the building permit cannot be released until the required septic permit is issued122.
- Apply through Public Works if the county-road driveway is new, altered, changing use, or lacks an access permit number3031.
- Submit complete plans and the required supporting documents to Community Development; residential issuance generally takes about 2 to 4 weeks, but missing items or unresolved land-use conditions cause delays216.
- Budget after plan review because permit fees depend on project cost, construction type, and square footage17.
- Complete required inspections and obtain a certificate of occupancy or temporary certificate before moving into a new dwelling or townhouse18.
What should you check before you buy land in Polk County?
Confirm the zoning district and whether the parcel sits inside an urban growth boundary, since UGB parcels can trigger city coordination and a longer permit review32. Ask Polk County Environmental Health for a septic site evaluation before you make an offer; with only about 3.5% of the county's soils rated free of severe limits for a conventional drain field, many parcels need an engineered or alternative system23. A landowner drilling a well must obtain a state landowner permit and bond before starting; the filing includes a $10,000 bond or letter of credit and a $550 permit fee33. Check whether the parcel is in a mapped floodplain: development there needs review through Community Development even for grading, filling, paving, or excavation alone, not just new construction34. If access is from a county road, verify the driveway already has an approach permit number, since a new or changed driveway needs its own Public Works permit before you build, and a driveway onto a state highway needs a separate Oregon Department of Transportation permit30. Do not assume acreage can be divided later: Polk County regulates partitions and subdivisions through the Planning Division, and subdivision applications receive a public hearing and written decision35. Polk County's median property tax bill runs about $3,534 a year at an effective rate near 0.8%3637.
Watch-outs
- Building permits in unincorporated Polk County cannot be released until the required septic permit has been applied for and issued, so start with Polk County Environmental Health17.
- Development inside a mapped floodplain needs county review even for grading, filling, or excavation alone, not just new construction, so check with Community Development before any site work34.
- A new, altered, or previously unpermitted driveway onto a county road needs its own Public Works access permit before you build; a driveway onto a state highway needs an Oregon Department of Transportation permit instead30.
- Do not treat a Timber Conservation campground allowance as permission to live in an RV: the campground use is temporary, conditional, and not residential38.
- Short-term rental use, standalone tiny-home occupancy, and any minimum dwelling floor-area requirement are not established in Polk County's published zoning materials as of this review; confirm each with the Planning Division before relying on an assumption26.
Sources
- Residential Building Permits (2026 county census)
- Permit Process, quoted and re-checked
- Residential Building Permits, quoted and re-checked
- Onsite Wastewater Treatment Program (2026 county census)
- Onsite Wastewater Treatment Program, quoted and re-checked
- Residential Building Permits (2026 county census)
- Onsite Wastewater Treatment Program, quoted and re-checked
- Oregon Revised Statutes Chapter 455, quoted and re-checked
- polkcountyor.gov, quoted and re-checked
- polkcountyor.gov, quoted and re-checked
- Chapter 118 — Accessory Dwelling Units, quoted and re-checked
- Chapter 118 — Accessory Dwelling Units, quoted and re-checked
- Oregon Revised Statutes, ORS 446.125 Occupancy on private land (Oregon statewide rule), quoted and re-checked
- Residential Structures Code Program, quoted and re-checked
- Residential Building Permits, quoted and re-checked
- Polk County Community Development – Building Division (polkcountyor.gov)
- Permit Process, quoted and re-checked
- 2023 Oregon Residential Specialty Code - Chapter 1, quoted and re-checked
- polkcountyor.gov, quoted and re-checked
- Onsite Wastewater Treatment Program, quoted and re-checked
- Onsite Wastewater Treatment Program, quoted and re-checked
- Polk County Environmental Health – Onsite Wastewater Treatment Program (polkcountyor.gov)
- Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
- polkcountyor.gov, quoted and re-checked
- What do I do with the finished material? (Oregon statewide rule), quoted and re-checked
- Polk County Community Development – Planning Division (polkcountyor.gov)
- Chapter 177 Timber Conservation Zoning District, quoted and re-checked
- Polk County Zoning Ordinance Chapter 127, quoted and re-checked
- Polk County Zoning Ordinance Chapter 127, quoted and re-checked
- Permit Application Information, quoted and re-checked
- Polk County Public Works (polkcountyor.gov)
- Permit Process, quoted and re-checked
- Landowner Constructed Wells, quoted and re-checked
- Flood Protection Information, quoted and re-checked
- Chapter 91: Subdivisions, Partitions, and Property Line Adjustments, quoted and re-checked
- Median property tax bill: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Chapter 177 — Timber Conservation (TC) Zoning District, quoted and re-checked
Written October 9, 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.