ADU Rules in Springfield, Oregon

Springfield is an independent city on the east bank of the Willamette River in Lane County, directly adjacent to — but completely separate from — Eugene. This distinction is critical: Springfield and Eugene share a metropolitan area and are physically connected, but they are different cities with different governments, zoning codes, fees, and permit offices. If your property address says "Springfield," your ADU application goes to Springfield — not Eugene — regardless of how close you are to the city line.

Springfield has historically been more blue-collar and industrial than its neighbor, with a strong manufacturing heritage. Like all Oregon cities with over 10,000 residents, Springfield must comply with Oregon's landmark housing reform laws governing ADUs and middle housing.

Oregon Statewide ADU Law — Critical Context

Two Oregon laws govern ADU development in Springfield:

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. Springfield must comply, ending the city's ability to maintain single-family-only zoning.

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 Springfield Allows

Under the Springfield 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 spaces.
• Interior Conversion: Converting existing habitable space — basement, attic, or rooms — within the primary structure into a separate dwelling unit.
• Garage Conversion: Repurposing an existing detached or attached garage as a habitable ADU meeting Oregon building habitability standards.

One ADU per single-family lot is permitted by right under state law.

Size and Setback Standards

Oregon law prohibits Springfield from requiring ADUs smaller than 900 square feet or 75% of the primary dwelling floor area, whichever is less. Typical setback standards in Springfield's low-density residential zones for detached ADUs 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.

Urban Growth Boundary

Springfield maintains its own UGB coordinated with Lane County and Oregon DLCD, separate from Eugene's UGB. ADU permits are issued only for properties within Springfield city limits and inside Springfield's UGB. Properties in Lane County outside the UGB are subject to county rural land use regulations.

Willamette River and McKenzie River Flood Zones

Springfield sits at the confluence of the Willamette River and McKenzie River. Properties near either waterway may be in FEMA-designated flood hazard zones. 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 where applicable

Check your property's FEMA flood zone designation before designing. The Willamette River floodplain can extend significantly into residential areas after major rain events.

Seismic Considerations

Springfield, like Eugene and the broader Willamette Valley, faces moderate to high seismic hazard from the Cascadia Subduction Zone. Oregon DOGAMI maps liquefaction potential in Willamette Valley lowland areas. New ADU construction must meet Oregon's seismic building code standards.

Permit Process — Apply to Springfield, Not Eugene

This bears repeating: Springfield has its own Building Division and Planning Department. Eugene applications go to a different office.

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 Springfield Development and Public Works — (541) 726-3753 — springfield-or.gov

Disclaimer

ADU regulations in Springfield are subject to change. Always verify current requirements directly with the City of Springfield Development and Public Works Department. Do not apply to Eugene for Springfield properties. This page is for informational purposes only and does not constitute legal or planning advice.