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Rural residential

Land zoned to allow rural living on acreage. This is generally where a first dwelling is most likely to be achievable, and where second-dwelling options such as accessory dwellings or RVs are most likely to be available if the county permits them at all.

General planning information, not legal advice. Describes what generally applies in a district, not a specific property. Confirm with the county — how this works.

Statewide law only — Union County has not been researched here.

The districts on this page are the four rural classes Oregon law defines, not Union County’s own district codes, and every finding rests on state statute plus the county’s recorded position on the two optional housing statutes. The county’s development code adds requirements this does not capture.

This page describes the district rather than any parcel in it. Each pathway below carries the status Union County gives it and what approval turns on — including requirements a vacant parcel would not meet, such as a dwelling already standing. Nothing here has been judged against a particular situation; the planner is where a specific one gets tested against these — it opens with this district filled in.

What could go on this land

Union County, Rural residential — what Oregon law says about each kind of structure, and which of the remaining questions are the county’s to answer. Local values are not recorded here, because they change; the questions do not.

Tiny home? Prefab? Barndominium? What those mean legally
Tiny home
Not a category in Oregon law. A tiny home on a trailer chassis is generally a recreational vehicle, and the rules for those apply. A small house on a permanent foundation is a dwelling, and which kind depends on how it was built — on site, in a factory to the state building code, or in a factory to the federal standard. The three have different rules. Under ORS 446.003 the manufacturer's own identification is what separates a recreational vehicle from a manufactured dwelling, so the answer to what a given tiny home is legally can generally be read off its paperwork.
Prefab
Used in marketing for both a prefabricated structure under ORS 455.010 and a manufactured home under ORS 446.003. They are built to different codes and carry different siting rules, so which one is on offer is worth establishing before making an offer on land.
Barndominium
A shop building with living quarters. The living quarters are a dwelling and answer to the dwelling rules for the district; the agricultural building exemption in ORS 455.315 does not extend to them.
Mobile home
One of the three things ORS 446.003 groups together as a manufactured dwelling, alongside a residential trailer and a manufactured home.
Park model
A park model recreational vehicle is a recreational vehicle under ORS 446.003, however permanent it looks once sited.
  • House, built on siteThe ordinary form of a dwellingGenerally available

    Where a dwelling is available in a rural residential district, a house built on site is the form the district's standards are generally written around. Setbacks, height and lot coverage still apply, and approved sanitation and legal access are generally required before a permit issues.

    What it is, legally

    Built on the parcel to the Oregon Residential Specialty Code, inspected in place. This is the baseline category the others are defined against — ORS 446.003 excludes anything built to that code from the definition of a manufactured dwelling.

    What it turns on

    • A dwelling pathway is available for the parcel in the first place.

    Ask the county

    • Confirm the district's setback, height and lot coverage standards.
    • County provisions on structure type have not been researched here — confirm any design standards directly.

    Who decides what

    • Building code · Settled statewide

      The Oregon Residential Specialty Code is statewide. Counties administer it and inspect to it; they do not write their own.

      Ask: Nothing on the code itself. Ask which edition is in force and whether the county has adopted any local wildfire construction provisions, which is the one area where local additions are common. source

    • Setbacks, height, lot coverage and road frontage · The county decides

      Set district by district in the county's code. On rural land the setbacks from property lines, from the road, and — in farm and forest districts — from adjoining resource operations are the standards most likely to decide where on the parcel a house can go, or whether an odd-shaped parcel can hold one at all.

      Ask: Ask for the district's dimensional standards and any resource-land buffer setbacks, and whether the parcel meets the road frontage or access standard.

    Statewide law only · last verified September 7, 2026 · source

  • Modular or prefab buildingTreated as a building, not as a manufactured homeAvailable with conditions

    A prefabricated structure under ORS 455.010 is built to the state building code off site and regulated by the Building Codes Division rather than by the county building official. Once placed it is a building like any other, so the rules that follow manufactured homes do not follow it — and neither do the protections. Whether a dwelling is available in the district is still the prior question.

    What it is, legally

    A building manufactured or assembled in whole or substantial part using closed construction at an off-site location, as defined in ORS 455.010, and regulated by the state Building Codes Division rather than by the county. Once sited it is a building like any other: it is NOT a manufactured dwelling, and the rules that follow manufactured dwellings do not follow it.

    Commonly confused with

    • A manufactured home. The two are separate legal categories with separate law. A prefabricated structure is built to the same state building code as a site-built house; a manufactured home is built to the federal HUD standard. Which one a supplier is selling determines which rules apply, and marketing language does not reliably distinguish them.

    What it turns on

    • A dwelling pathway is available for the parcel in the first place.
    • The supplier is selling a prefabricated structure under ORS 455.010 rather than a manufactured home under ORS 446.003.

    Ask the county

    • Ask the county which of the two categories the unit falls in, and ask the supplier for the certification in writing — marketing language does not reliably distinguish them.
    • County provisions on structure type have not been researched here — confirm any design or foundation standards directly.

    Who decides what

    • Construction standard and plan approval · Settled statewide

      A prefabricated structure is built off site to the state building code under the Building Codes Division's Prefabricated Structures Program, which approves the plans and inspects the factory. The county building official inspects only what happens on site — foundation, connections, and any site-built portion.

      Ask: Ask the supplier for the state insignia of compliance and the approved plans; the county will need the on-site work permitted separately. source

    • Setbacks, height and lot coverage · The county decides

      Once placed it is a building like any other, so the district's dimensional standards apply exactly as they would to a site-built house — and nothing more, since it is not a manufactured home and the placement standards for those do not reach it.

      Ask: Ask for the district's setback, height and lot coverage standards. If the county cites manufactured-home placement standards, point out that a prefabricated structure under ORS 455.010 is a different category.

    Statewide law only · last verified September 7, 2026 · source

  • Manufactured homeA separate category, with county standardsAvailable with conditions

    A manufactured home under ORS 446.003 is built on a chassis to the federal standard rather than to the state building code, and is a distinct legal category from a prefabricated structure. Counties commonly apply siting and design standards to them — foundation, roof pitch, siding and age are the usual subjects — and those standards have not been researched for any county here. Whether a dwelling is available in the district remains the prior question.

    What it is, legally

    A residential trailer, mobile home or manufactured home under ORS 446.003 — built on a chassis to the federal standard rather than to the state building code. The statute is explicit that a unit meeting the definitions of both a manufactured dwelling and a recreational vehicle, but not identified by the manufacturer as a recreational vehicle, is a manufactured dwelling.

    Commonly confused with

    • A modular or prefabricated building, which is a different legal category built to a different code.
    • A park model recreational vehicle. The manufacturer's own identification of the unit is what separates them under ORS 446.003, not size, appearance or how it is marketed.

    What it turns on

    • A dwelling pathway is available for the parcel in the first place.
    • The unit meets whatever siting and design standards the county applies to manufactured homes.

    Ask the county

    • Ask for the county's siting and design standards for manufactured homes, including any limit on the age of the unit.
    • Ask whether the district treats a manufactured home differently from a site-built house for setbacks or foundation.

    Who decides what

    • Foundation, anchoring and installation · Settled statewide

      Every manufactured dwelling installed in Oregon is installed to the Oregon Manufactured Dwelling Installation Specialty Code — foundation, tie-downs, wind anchoring, setup — administered by the state Building Codes Division and inspected under it. This is the same everywhere in the state. A county planner cannot waive it and does not set it.

      Ask: Nothing to ask the county here. The installer works to the state code; ask the installer which edition applies and for the certified installation. source

    • Construction standard of the unit itself · Settled statewide

      A manufactured home is built to the federal HUD standard, not to the state building code, and Oregon regulates the units and their dealers under ORS chapter 446. A county does not inspect the construction of the unit.

      Ask: Ask the dealer for the HUD certification label and data plate. The county will ask for them at permit time. source

    • Placement standards · The county decides

      Outside an urban growth boundary a county's code can carry placement standards for manufactured homes beyond what it asks of a site-built house, and many do. They are drawn from a short, long-standing statutory template, so the kinds are predictable even where the figures are not: whether the unit must be multi-sectional; a minimum floor area; how high the unit may sit above grade and whether the perimeter must be enclosed; a minimum roof pitch; exterior siding and roofing comparable to nearby houses; a certified thermal envelope; and sometimes a limit on the unit's age. Inside a UGB, ORS 197.478 removes all of these except a thermal-envelope requirement.

      Ask: Ask for the county's placement standards for a manufactured home in this district, in writing, and specifically whether there is an age limit on the unit — that one decides whether a used home is an option at all. source

    • Setbacks, height and lot coverage · The county decides

      The district's dimensional standards apply to a manufactured home as they would to any dwelling. They are set district by district and revised with the code.

      Ask: Ask for the district's setback, height and lot coverage standards, and whether any overlay on the parcel changes them.

    Statewide law only · last verified September 7, 2026 · source

  • RV, park model or tiny home on wheelsOnly where the county adopted itAvailable with conditions

    A recreational vehicle is not a dwelling under ORS 446.003. ORS 215.490 lets a county allow one to be rented as a second dwelling on rural residential land, and that is a county-by-county adoption rather than statewide law. The statute generally requires an owner-occupied single-family dwelling already on the property, no other dwelling units, connection to power, potable water and sewage disposal, and it generally prohibits vacation occupancy. On a vacant parcel none of that is available, because the route depends on a house being there first. Two statewide provisions frame every county conversation about this: ORS 446.125 generally permits occupying a camping vehicle on private land with the owner’s consent where approved water supply and sewage disposal exist — a habitability rule, not a zoning permission — and ORS 197.493 bars a county from prohibiting occupancy solely because the vehicle is a recreational vehicle in three named situations.

    What it is, legally

    A vehicle designed for human occupancy and to be used TEMPORARILY for recreational, seasonal or emergency purposes, under ORS 446.003. The word temporarily is doing the work: a recreational vehicle is not a dwelling in Oregon law, so permission to live in one is a separate question from permission to have a dwelling, and it is answered by separate rules. A park model recreational vehicle is a recreational vehicle. A tiny home built on a trailer chassis is generally one too.

    Commonly confused with

    • A tiny home on a permanent foundation, which is not a recreational vehicle at all and is assessed as whichever dwelling category it was built under.
    • A manufactured home. Under ORS 446.003 a unit meeting both definitions is a manufactured dwelling unless the manufacturer identified it as a recreational vehicle — so the factory label decides this, and it is worth reading before buying rather than after.

    What it turns on

    • The county has adopted the ORS 215.490 option.
    • A single-family dwelling already stands on the property and is occupied by the owner as their primary residence.

    Ask the county

    • Confirm whether the county has adopted the recreational vehicle second-dwelling option, and its local conditions including any acreage minimum.
    • Ask separately whether temporary occupancy during construction of an approved dwelling is allowed.
    • Ask what water supply and sewage disposal the county will accept for a recreational vehicle on the parcel — under ORS 446.125 that question is reached before the zoning one.

    Who decides what

    • Baseline occupancy on private land · Settled statewide

      ORS 446.125 generally permits a person to occupy a camping vehicle on privately owned land with the owner's consent, provided the land has adequate area for a safe and approved water supply and sewage disposal and the occupant meets state and local sanitation, water, plumbing and electrical standards. It is a habitability provision, not a land use permission — it does not override zoning — but it is why the sanitation question comes first in nearly every conversation about this.

      Ask: Ask what water supply and sewage disposal the county will accept for a recreational vehicle on the parcel — that question is decided before the zoning one is reached. source

    • Where a county may not prohibit occupancy · Settled statewide

      ORS 197.493 generally bars a local government 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 ORS 215.490 applies; where the vehicle is in a manufactured dwelling, mobile home or RV park and is lawfully connected to water, power and sewage disposal; and where the dwelling on the lot was made uninhabitable by a natural disaster, for a limited period. A county saying occupancy is not permitted is generally speaking about ordinary private land, and those three are worth raising by name.

      Ask: If one of the three situations applies, ask the county how it treats it, citing ORS 197.493. source

    • Zoning treatment of an occupied vehicle · The county decides

      Outside those situations, whether a recreational vehicle may be lived in on a parcel, for how long, and on what conditions is the county's zoning code — set district by district, and the part that varies most from county to county.

      Ask: Ask whether an occupied recreational vehicle is allowed in this district, whether that depends on a house already being there, for how long, and whether temporary occupancy during construction of an approved dwelling is a separate route.

    Statewide law only · last verified September 7, 2026 · source

  • Barn, shop or outbuildingGenerally available, under district standardsAvailable with conditions

    A building with no dwelling use is generally available in rural residential districts, subject to the district's size, height, setback and lot coverage standards. The agricultural building exemption in ORS 455.315 turns on the parcel being a farm rather than on the district, so it commonly does not reach a rural residential lot — and where it does not, an ordinary building permit is required.

    What it is, legally

    A structure with no dwelling use. Where it qualifies as an agricultural building on a farm, ORS 455.315 exempts it from the structural code and from a building permit — but that exemption is narrower than it is usually understood to be, and what it does not cover is set out per district below.

    Commonly confused with

    • A shop with living quarters, sometimes marketed as a barndominium. The living part is a dwelling and is assessed as one; the exemption for agricultural buildings does not reach it.

    What it turns on

    • The building meets the district's size, height, setback and lot coverage standards.

    Ask the county

    • Ask what size an accessory building may be in this district before additional review is triggered.
    • Ask whether the parcel qualifies for the ORS 455.315 agricultural building exemption, and assume a building permit is required unless the planning department confirms otherwise.

    Who decides what

    • Agricultural building exemption · Settled statewide

      ORS 455.315 is statewide. What it exempts — the structure of an agricultural building on a farm, from the structural code and a building permit — and what it does not — electrical, plumbing, mechanical, and land use approval — does not vary by county.

      Ask: Ask the planning department, not the building official, whether the parcel qualifies as a farm for the exemption; the statute leaves that determination to them. source

    • Size, height, setbacks and permit threshold · The county decides

      Where the exemption does not apply, the county's code sets how large an accessory building may be before it needs a permit or triggers review, its height, and its setbacks — and whether a shop with plumbing or a sleeping area is treated as something other than an accessory building.

      Ask: Ask the size below which no building permit is needed, the height limit, the setbacks, and how the county treats a shop that has plumbing or living space.

    Statewide law only · last verified September 7, 2026 · source

What the county's code adds — and what it does not decide

  • Septic feasibility and approval · Settled statewide

    On-site sewage disposal is regulated by the Department of Environmental Quality statewide, and administered in most counties under contract. Whether the soil will take a system, and what kind, is a site evaluation — the county's zoning code does not decide it and a listing cannot.

    Ask: Ask whether a site evaluation has been done for the parcel and what system type it approved; if none, that evaluation is the first money to spend. source

  • Domestic well · Settled statewide

    Well construction and water rights are the Water Resources Department's. A domestic well is generally exempt from a water right, but the well itself is regulated statewide, and in some basins groundwater is restricted.

    Ask: Ask the Water Resources Department whether the parcel is in a groundwater-restricted area, and look up neighbouring well logs for likely depth. source

  • Minimum parcel size and lot of record · The county decides

    Whether a parcel is large enough for a dwelling, and whether it was lawfully created, are the county's determinations under its own code and the state's lot-of-record rules. They turn on the parcel's history rather than its listing.

    Ask: Ask the county to confirm the parcel is a lawfully created lot of record and meets the district's minimum size for a dwelling.

  • Setbacks, height, lot coverage and access · The county decides

    The district's dimensional standards and the county's road and access standards decide where on the parcel anything can go, and whether legal access exists. Revised with the code; ask rather than assume.

    Ask: Ask for the district's dimensional standards and the county's access requirements, and whether the parcel's access is legal access of record.

  • Wildfire and fire protection · State and local

    The statewide wildfire hazard map was repealed in 2025, and with it the statewide construction and defensible-space rules it triggered; counties may adopt their own. Whether the parcel is inside a rural fire protection district is a separate question that decides both insurability and some dwelling routes.

    Ask: Ask whether the county has adopted local wildfire construction or defensible-space standards, and confirm which fire protection district, if any, covers the parcel. source

Hold the land as-is

Generally available

Holding land without placing a dwelling on it is generally available. Under Oregon’s assessed value limit, the tax base on unimproved land generally grows slowly until new construction occurs.

Ask the county

  • This county has not been researched here, so confirm everything below directly with its planning department.

Last verified August 16, 2026 · source

Live on site temporarily while building

Not yet researched

Temporary occupancy arrangements are set county by county and have not been researched for this county.

Ask the county

    Build a primary dwelling

    Available with conditions

    Rural residential districts are generally the most likely rural districts to support a first dwelling, subject to the county’s development standards, approved sanitation, legal access and applicable setbacks. This reflects statewide law only — the county has not been researched here, and its own provisions may add requirements or narrow this further.

    What it turns on

    • An approved septic system or other accepted sanitation arrangement is in place

    Ask the county

    • This county has not been researched here, so confirm everything below directly with its planning department.
    • Confirm the dwelling application type, review timeline and fees for this district.

    Last verified August 16, 2026 · source

    Add an accessory dwelling unit

    Available with conditions

    This county is recorded as allowing rural accessory dwelling units. State law commonly conditions them on a parcel of at least two acres with an existing single-family dwelling, a floor area limit of 900 square feet, siting within 100 feet of that dwelling, service by a fire protection provider, sanitation compliance, and a prohibition on vacation rental use. Under state law a property generally may have either an accessory dwelling unit or a rented recreational vehicle, but not both. This reflects statewide law only — the county has not been researched here, and its own provisions may add requirements or narrow this further. Recorded for Union: Adopted accessory dwelling units in the R-1, R-2, R-3 and R-4 zones by Ordinance 2024-03 (second reading August 21, 2024): at least two acres, an existing single-family dwelling, fire protection district service, within 100 feet, 900 square feet, no vacation or short-term occupancy, approved by the Planning Commission as a conditional use after a public hearing with a $300 application fee, and excluded in the Medical Springs and Pondosa area.

    What it turns on

    • Parcel is at least 2 acres
    • Property already has a single-family dwelling
    • Unit is no more than 900 square feet
    • Parcel is served by a fire protection service provider
    • An approved septic system or other accepted sanitation arrangement is in place
    • Unit is not used as a vacation rental

    Ask the county

    • This county has not been researched here, so confirm everything below directly with its planning department.
    • Confirm the county’s current standards, the districts they reach, and which wildfire construction provisions apply.

    Last verified September 9, 2026 · source

    Use or rent an RV as a second dwelling

    Not yet researched

    The state option allowing a recreational vehicle as a second dwelling is adopted county by county, and this county’s position has not been established here. That is an open question rather than a no. Recorded for Union: Adopted accessory dwelling units in the R-1, R-2, R-3 and R-4 zones by Ordinance 2024-03 (second reading August 21, 2024): at least two acres, an existing single-family dwelling, fire protection district service, within 100 feet, 900 square feet, no vacation or short-term occupancy, approved by the Planning Commission as a conditional use after a public hearing with a $300 application fee, and excluded in the Medical Springs and Pondosa area.

    Ask the county

    • This county has not been researched here, so confirm everything below directly with its planning department.
    • Confirm whether the county has adopted the RV second-dwelling option since this was last checked.

    Last verified September 9, 2026 · source

    Rent it short-term

    Not yet researched

    Oregon has no statewide short-term rental permit scheme, so treatment varies entirely by county and has not been researched here. Lodging taxes may apply regardless of whether a permit is required. Note that this pathway presupposes a lawfully established dwelling to let. Note separately that state law generally bars vacation occupancy of both a rural accessory dwelling unit and a rented recreational vehicle.

    What it turns on

    • Property already has a single-family dwelling

    Ask the county

    • This county has not been researched here, so confirm everything below directly with its planning department.
    • Ask whether the county licenses short-term rentals, and which lodging taxes apply.

    Last verified August 16, 2026 · source

    Seek a rezone or plan amendment

    Not yet researched

    This pathway exists to change resource land to a non-resource designation. Land already zoned rural residential has nothing to change.

    Ask the county