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References and methodology

Everything this tool says is derived from published county and state materials, encoded by hand with a source and a date. This page sets out how it works and where it stops.

What this tool does not do

  • It does not determine a parcel’s zoning. An address, a listing link or a map pin can be turned into a point and Oregon’s statewide zoning layer asked what district covers it — but the result is shown as that layer’s report, applied only when you confirm it, refused when the address matched a road rather than a property, and never stored. Nothing here looks up an owner, a tax lot or a property’s history, and the answers describe the district, not the parcel.
  • It does not determine what is permitted. Counties decide these questions case by case on the facts of a parcel, and several of the tests involved turn on history and site conditions that cannot be assessed from a desk.
  • It does not predict septic feasibility, well yield or permit timelines. A site evaluation with test pits is the only way to establish sanitation feasibility.
  • It is not legal advice or land-use advice, and it is not a substitute for either.

How options are produced

Each county’s local district codes are mapped to a broader class — exclusive farm use, forest, mixed farm and forest, or rural residential. Rules are recorded against those classes with structured conditions, so a requirement such as a minimum parcel size or an existing dwelling is evaluated rather than merely described.

Conditions resolve to met, not met, or unknown. Unknown is used deliberately and often: many requirements genuinely cannot be resolved without site work or county review. Treating those as met would overstate certainty, and treating them as failures would understate the options. Unknown conditions lower the confidence attached to an option and are listed explicitly on it.

Up to three options are lettered, each with its tradeoffs, the conditions that generally apply, the questions to take to the county, and a disclaimer generated from that option’s own confidence and unmet conditions. Often it is one. When nothing appears available, the tool says so rather than presenting a weak option as a plan.

How options are ranked

Each pathway carries a fixed score against each priority — building a home scores highest for living there full time and for building soon, a rented RV for vacation use and rental income, and so on — and an option’s rank is the sum over the priorities you selected. Neither a rural accessory dwelling nor a rented RV scores for short-term letting, because state law generally bars vacation occupancy of both. Ties fall to the order the pathways are listed in.

Two adjustments run before the ranking. In a farm or forest district, where a new dwelling turns on a narrow statutory test, dwelling pathways are held out of the lettered options entirely and shown separately as narrow exceptions, whatever priorities were chosen — wanting a house does not make one available. And holding the land as it is, which is permitted everywhere, is lettered only when holding or minimising cost is among your priorities; otherwise it is set aside with the one thing worth knowing about it, which is what happens to a special assessment.

Confidence is high when every condition on the rule is met, medium with one or two unresolved, low with more — and low regardless when the rule itself is unverified, when the county’s position is only under consideration, when the district is farm or forest and anything is unresolved, when three or more major items such as water, power, sanitation or legal access are outstanding, or when the rule was last verified more than 180 days ago. A pathway whose county position could not be established is listed as an open question, never ranked or costed.

Cost assumptions

Every figure the planner uses — site improvements, the six construction methods with their evidence grades, financing tiers, and how property tax is treated — sits with the numbers it explains, on the build methods page.

Sources

Oregon — statutes and statewide rules

  • ORS 215.490 — recreational vehicle as a second dwelling (SB 1013, 2023)

    Allows a county to permit one recreational vehicle used for residential purposes under a rental agreement on rural residential property. Adoption is discretionary — a county must take it up locally before it has any effect there. Conditions in the statute generally include that the property is in a rural area and not within an urban reserve, that a single-family dwelling occupied as the owner's primary residence is sited on the property, that there are no other dwelling units and the primary dwelling is not itself rented, that the tenant owns or leases the recreational vehicle, and that the owner provides essential services to the recreational vehicle space. Notably the statute itself sets no minimum parcel size — acreage minimums seen in particular counties are local conditions. The statute generally prohibits use of the recreational vehicle for vacation occupancy as defined in ORS 90.100, or other short-term uses.

    Last verified August 16, 2026 · source

  • ORS 197.493 — limits on prohibiting recreational vehicle occupancy

    Generally prevents state agencies and local governments from prohibiting residential occupancy of a recreational vehicle, or limiting how long it may be occupied, solely because it is a recreational vehicle, in three situations: where the use is allowed under ORS 215.490; where the vehicle is in a manufactured dwelling, mobile home or recreational vehicle park and is lawfully connected to water, electrical supply and a sewage disposal system; and where the vehicle is on a lot whose dwelling was made uninhabitable by a natural disaster, generally for a limited period. This matters because a county statement that recreational vehicle occupancy is not permitted is generally addressing occupancy on ordinary private land, and does not necessarily describe these situations. Worth raising directly with the county if one of them applies.

    Last verified August 16, 2026 · source

  • ORS 446.125 — occupancy of a manufactured dwelling or camping vehicle on private land

    Generally permits a person to occupy a manufactured dwelling or camping vehicle on privately owned land with the landowner's consent, provided the property has adequate area for a safe and approved water supply and sewage disposal, and the occupant complies with applicable state and local standards for sanitation, water, plumbing, electrical and sewerage installations. This is a baseline habitability and sanitation provision rather than a land use permission, so it generally does not override a county's zoning treatment of recreational vehicles — but it is the reason sanitation and utility connection questions come up first in almost every county conversation about this.

    Last verified August 16, 2026 · source

  • Senate Bill 391 (2021), amended by SB 644 (2023)

    Allows counties to permit accessory dwelling units in rural residential zones. Commonly cited conditions include a minimum parcel size of two acres, an existing single-family dwelling, a floor area limit of 900 square feet, siting within 100 feet of the existing dwelling, service by a fire protection provider, compliance with sanitation requirements, a prohibition on vacation rental use, and no division of the parcel to separate the unit.

    Last verified August 15, 2026 · source

  • ORS 308A — farm and forest special assessment

    Land in farm or forest use is generally assessed on its value in that use rather than its market value, which is usually why a large rural parcel carries a strikingly small tax bill. The assessment is tied to the land continuing in that qualifying use. If it is disqualified — commonly by the use stopping, or by a change to a non-qualifying use — additional tax is generally added to the next tax roll. For designated forestland that additional tax is generally the difference between what was paid over the previous five years and what would have been paid at real market value. Critically for a buyer, the special assessment attaches to the land, so the potential liability generally passes to the new owner on sale rather than staying with the seller. Continuing the qualifying use, or requalifying, can defer or avoid it.

    Last verified August 16, 2026 · source

  • Measure 50 assessed value limit

    Limits growth in a property's maximum assessed value to three percent per year, with new construction treated as an exception. In general terms this means holding unimproved land tends to have a low and slow-growing tax base, while adding a dwelling generally causes a step change in assessed value rather than a gradual increase.

    Last verified August 15, 2026 · source

  • Statewide wildfire hazard map repeal (2025)

    In 2025 the Legislature repealed the statewide wildfire hazard map together with its application to seller disclosures, wildfire-related building code standards and defensible space requirements, and directed development of new standards that property owners or local governments may adopt. Some housing statutes refer to that map, so the branch of those statutes that applies when no statewide map exists is generally the operative one. This area is unsettled and worth confirming locally.

    Last verified August 15, 2026 · source

  • Goal exceptions and non-resource rezoning (ORS 197.732)

    Changing the zoning of farm or forest land is generally expected to happen through a county or region wide legislative review, through a goal exception meeting stringent statutory criteria, or by demonstrating through a plan amendment and zone change that the property does not meet the definition of agricultural land. General market demand, past development, or market trends are generally not treated as sufficient grounds on their own. This boundary generates a large share of appeals to the Land Use Board of Appeals, so it is best treated as a specialist legal undertaking rather than a routine application.

    Last verified August 15, 2026 · source

  • Farm and forest zone dwelling limits

    State rules generally prohibit new dwellings in exclusive farm use and forest zones unless a specific statutory test is met. Commonly cited paths include a dwelling for a farm operator, a dwelling for a relative assisting the farm operation, farmworker housing, a lot of record dwelling, and a nonfarm dwelling on land shown to be unsuitable for farm or forest production. Each is a fact-intensive test decided by the county, not an automatic entitlement.

    Last verified August 15, 2026 · source

Counties

5 of Oregon’s 36 counties have had their own development code read, and their rules are listed below with a source and a date each. The other 31 are answered from the statutes above plus the county’s recorded position on the two optional rural housing statutes, which is sourced on the Oregon page. Every page for one of those counties says so.

Washington County

  • raw hold — verified August 16, 2026 · source
  • raw hold — verified August 15, 2026 · source
  • second dwelling rv — verified September 9, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • temporary occupancy during construction — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 15, 2026 · source
  • non resource rezone — verified August 15, 2026 · source
  • short term rental — verified September 9, 2026 · source

Clackamas County

  • raw hold — verified August 16, 2026 · source
  • raw hold — verified August 15, 2026 · source
  • second dwelling rv — verified September 9, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • temporary occupancy during construction — verified August 15, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 15, 2026 · source
  • non resource rezone — verified August 15, 2026 · source
  • short term rental — verified August 15, 2026 · source

Deschutes County

  • raw hold — verified August 16, 2026 · source
  • raw hold — verified August 16, 2026 · source
  • second dwelling rv — verified September 9, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • non resource rezone — verified August 16, 2026 · source
  • short term rental — verified August 16, 2026 · source
  • temporary occupancy during construction — verified August 16, 2026 · source

Lane County

  • raw hold — verified August 16, 2026 · source
  • second dwelling rv — verified September 9, 2026 · source
  • second dwelling adu — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • short term rental — verified August 16, 2026 · source
  • temporary occupancy during construction — verified August 16, 2026 · source
  • primary dwelling — verified August 26, 2026 · source
  • primary dwelling — verified August 26, 2026 · source
  • primary dwelling — verified August 26, 2026 · source
  • non resource rezone — verified August 26, 2026 · source
  • second dwelling rv — verified August 26, 2026 · source
  • temporary occupancy during construction — verified August 26, 2026 · source
  • short term rental — verified August 26, 2026 · source

Columbia County

  • raw hold — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • primary dwelling — verified August 16, 2026 · source
  • second dwelling adu — verified August 16, 2026 · source
  • second dwelling adu — verified September 9, 2026 · source
  • second dwelling rv — verified September 9, 2026 · source
  • temporary occupancy during construction — verified August 16, 2026 · source
  • non resource rezone — verified August 16, 2026 · source
  • short term rental — verified August 16, 2026 · source