Accessory Structures in Oregon (2026)

Under ORS 197A.425, Oregon cities over 2,500 population and counties over 15,000 must allow at least one accessory…

Beaverton allows one accessory dwelling unit per single-detached home through a staff-level Type 1 permit, capped at…

In unincorporated Benton County, an accessory dwelling unit is allowed only where zoning permits it inside an urban…

In unincorporated Clackamas County, ZDO Section 839 allows one ADU per single-family dwelling. Inside an urban growth…

Eugene allows one accessory dwelling per lot in every residential zone under EC 9.2751(17), capping an attached ADU at…

Gresham allows one Accessory Dwelling per single detached dwelling, capped at 900 square feet or 75 percent of the…

Hillsboro allows one accessory dwelling unit per single detached dwelling or townhouse, sized between 250 and 750…

Lane County allows one accessory dwelling unit per lot in the Rural Residential zone under Lane Code section 16.290(8)…

Medford allows one ADU per single-family, duplex or townhouse lot, capped at 900 square feet or 75 percent of the…

In the Rural Residential zone, unincorporated Multnomah County allows one accessory dwelling unit per single-family…

Portland caps accessory dwelling units at 800 square feet or 75% of the primary home's living area, whichever is…

Salem caps an accessory dwelling unit at 900 square feet or 75 percent of the main house's gross floor area, whichever…

Washington County allows up to two Urban Accessory Dwelling Units on a single-family lot in the unincorporated urban…

Oregon law requires Marion County and its cities to allow at least one accessory dwelling unit (ADU) for each detached…

Accessory dwelling units in unincorporated Clackamas County are not exempt from the county's Transportation System…

Lane County charges its Parks and Recreation System Development Charge on every new dwelling built in the…

Medford cuts a homeowner's Street System Development Charge in half for an accessory dwelling unit of 900 square feet…

Salem charges system development charges (SDCs), its impact fees for water, wastewater, stormwater, transportation, and…

A recorded Beaverton HOA covenant or CC&R cannot require an accessory dwelling unit to be owner-occupied. Development…

Once a property in unincorporated Benton County has an accessory dwelling unit, neither the ADU nor the primary house…

Gresham's Development Code flatly bars Accessory Dwellings from being used as short-term rentals, closing off a popular…

An ADU that gets Medford's 50% Street SDC exemption cannot be rented short-term for 10 years afterward. The restriction…

Multnomah County bars short-term rental of accessory dwelling units in rural residential zones like MUA-20 outside…

Salem bars accessory dwelling units from operating as short-term rentals or accessory short-term rentals. The rule sits…

Rural accessory dwelling units in unincorporated Washington County cannot be rented out as vacation rentals. CDC §§…

Beaverton caps combined accessory-structure footprint at 500 square feet on lots up to 10,000 square feet (700 on…

In the Rural Residential zone of unincorporated Benton County, BCC § 63.405(5) lets a shed or other non-residential…

In unincorporated Clackamas County, ZDO Section 315 sets accessory-building setbacks. A shed behind the building line…

Eugene caps accessory buildings, sheds, detached garages and workshops, at 10 percent of the lot area under EC…

Gresham's Development Code sets sliding setbacks for backyard sheds and other detached accessory structures based on…

Backyard sheds, detached garages and other accessory structures in Hillsboro follow Community Development Code §…

Sheds, garages, greenhouses and other accessory structures are a permitted use on rural residential (RR) land in…

A carport is a residential accessory structure in Marion County. Its peak height is nine feet at the lot line…

In unincorporated Multnomah County's LR-5 residential zone, a detached carport must sit behind the house's rear line or…

Portland caps detached sheds and other covered accessory structures at 20 feet tall, holds them to standard building…

In Salem's RS single-family zone, accessory structures such as sheds are capped at 15 feet in height and a combined 600…

Detached sheds and other residential accessory buildings in unincorporated Washington County can't cover more than 25%…

Converting a garage into an accessory dwelling unit is allowed in Beaverton, but unlike a basement or attic conversion…

Hillsboro allows homeowners to convert an existing garage into an accessory dwelling unit (ADU) under Community…

In Marion County, an attached garage converted to living space is treated as part of the dwelling and must meet the…

Medford values a garage conversion to habitable space at 50 percent of the "R-3 Residential" rate on the ICC Building…

Converting an attached garage into an accessory dwelling unit is the one case in Washington County's ADU code where the…

Oregon requires every city over 2,500 people and every county over 15,000 to allow at least one accessory dwelling unit…

Beaverton has not adopted Appendix Q's special tiny-house standards, so a tiny house here must meet the same full…

Benton County will not issue a building permit for a tiny house on wheels, classified as a Group R-5 wheeled…

In Multnomah County's Multiple Use Agriculture (MUA-20) zone, an accessory dwelling unit must be a permanent structure…

A tiny house on a permanent foundation is treated as a dwelling or ADU under Lane Code 16.290 and must meet building…

Marion County has no tiny-home-specific ordinance. A permanent tiny house on a foundation is regulated as a dwelling or…