ADU Rules in Albany, Oregon

Albany, the seat of Linn County, is a city of approximately 55,000 residents situated at the confluence of the Willamette River and Calapooia River in the heart of the Willamette Valley. Albany is notable for its exceptionally preserved historic downtown — one of the largest collections of historic buildings in Oregon — and for its role as a national center for rare and specialty metals manufacturing, including titanium and zirconium processing. Located between Salem and Eugene on the I-5 corridor, Albany has a working-class manufacturing identity while managing growth from the broader valley. ADU construction follows the Albany Development Code alongside Oregon's statewide housing reform mandates.

Oregon Statewide ADU Law — Critical Context

Two Oregon laws govern ADU development in Albany:

Oregon HB 2001 (2019) requires cities with populations over 10,000 to allow middle housing — duplexes, triplexes, fourplexes, and cottage clusters — in all residential zones. Albany, with over 55,000 residents, must comply, ending single-family-only zoning and requiring the city to update its Development Code to permit a range of residential densities throughout the city.

Oregon's statewide ADU framework is SB 1051 (2017) plus HB 2001 (2019) middle housing. HB 2098 (2021) is a rental-assistance bill, not ADU.

What Albany Allows

Under the Albany Development Code and state law, the following ADU types are permitted in residential zones:

• Detached ADU: A freestanding structure on the same lot as the primary home, with its own kitchen, bathroom, and entrance.
• Attached ADU: An addition to the primary dwelling with a dedicated separate entrance and self-contained living facilities.
• Interior Conversion: Converting existing habitable space — basement, attic, or rooms within the primary structure — into a separate dwelling unit.
• Garage Conversion: Converting an existing attached or detached garage into habitable ADU space meeting Oregon building code standards.

One ADU per single-family lot is permitted by right. Albany's updated code under HB 2001 may allow additional density on eligible lots.

Size and Setback Standards

Oregon law prohibits Albany from requiring ADUs smaller than 900 square feet or 75% of the primary dwelling's floor area, whichever is less. Standard setbacks for detached ADUs in Albany's residential zones typically include:

• Rear setback: 5 feet minimum
• Side setback: 5 feet minimum
• Height: Generally 15–18 feet maximum for detached ADUs

Existing legal nonconforming structures being converted to ADUs may maintain their existing setbacks even if they do not conform to current new-construction standards.

Willamette River and Calapooia River Flood Zones

Albany sits at the confluence of two rivers, and flooding is a significant land use consideration. Substantial portions of Albany are in FEMA-designated flood hazard zones (Zone AE), particularly in lower-lying areas near the Willamette River and Calapooia River and their associated floodplains. ADU construction in flood zones requires:

• Elevated foundations: At or above the Base Flood Elevation (BFE)
• Flood-resistant construction materials: Below the BFE
• Floodplain development permits: Required in addition to standard building permits for some properties

Check your property's FEMA flood zone designation through FEMA's Flood Map Service Center or the Albany Planning Division before committing to an ADU design. Albany's flood hazard areas are more extensive than in many Willamette Valley cities due to the dual river confluence.

Historic District Overlays

Albany has one of the most extensive historic districts in Oregon, with multiple National Register of Historic Places districts covering thousands of historic buildings. Some historic overlay protections extend into adjacent residential neighborhoods. ADU construction within a historic overlay may require:

• Design review for architectural compatibility
• Review of exterior materials, massing, and design elements
• Additional approval timeline before building permit issuance

Verify whether your property is in a historic overlay zone with the Albany Planning Division before designing your ADU. Historic review is separate from and in addition to standard building permit review.

Urban Growth Boundary

Albany's UGB is coordinated with Linn County and Oregon DLCD. ADU permits are issued only for properties within Albany city limits and the UGB. Properties in Linn County outside the UGB — including agricultural and rural lands — are subject to county zoning that does not permit residential ADUs.

Seismic Considerations

Albany, in the Willamette Valley, faces moderate to high seismic hazard from the Cascadia Subduction Zone. Oregon DOGAMI maps significant liquefaction potential in Willamette Valley lowland areas, particularly near river courses. New ADU construction must meet Oregon's seismic building code standards.

Permit Process

Oregon's statewide ADU framework is SB 1051 (2017) plus HB 2001 (2019) middle housing. HB 2098 (2021) is a rental-assistance bill, not ADU.

Contact: City of Albany Planning Division — (541) 917-7550 — cityofalbany.net/departments/planning

Disclaimer

ADU regulations in Albany — including flood zone and historic district requirements — are subject to change. Always verify current standards with the City of Albany Planning Division and Building Division. This page is for informational purposes only and does not constitute legal or planning advice.