What is Portland's Residential Infill Project (RIP), and what does it allow?
Answered by AskBaily Editorial · Updated
Short answer
The Residential Infill Project, adopted 2020, reformed Portland's single-family zoning to allow up to four units (duplex, triplex, fourplex) on most R5 / R7 / R10 lots, plus cottage cluster developments of up to six units. RIP preempted most prior single-family-only restrictions, capped parking minimums, and scaled housing density. It is the single biggest zoning reform Portland has shipped in a generation.
In detail
The Residential Infill Project (RIP) is the most consequential zoning reform Portland has shipped in a generation. Adopted by City Council in August 2020 and codified into Title 33 of the Portland Zoning Code (primarily Chapters 33.110 and 33.120), RIP rewrote single-dwelling residential zoning to allow up to four dwelling units (duplex, triplex, fourplex) on most R5, R7, R10, and R20 lots citywide. The reform replaced a regime that had effectively been single-family-only since the early 20th century. Key provisions are concentrated in 33.110.240 (Housing Types) and 33.110.250 (Density). On a typical R5 lot (5,000 square foot minimum), an owner can now build up to four units by-right, and up to six units when the project meets the affordable-housing bonus criteria in 33.110.246. Cottage cluster development is permitted on lots of 7,000 square feet or larger under 33.110.245, allowing six smaller detached units around a shared courtyard. RIP also capped parking minimums at zero for most residential development under 33.266.110, removed minimum lot-size doubling for duplexes, and revised setback and floor-area-ratio standards to make four-plex envelopes physically buildable. Demolition triggers a separate 35-day demolition delay under 33.235 if the existing structure is over 25 years old. The reform did not eliminate design review in historic districts, environmental overlay zones, or Coastal Resource overlays — those layers still apply on top of the underlying base zone. Phase 2 of RIP (formally adopted in 2022 as the Expanding Opportunities for Affordable Housing project) extended similar density flexibility to additional zone categories. Practical implication for a homeowner: a typical R5 lot in Northeast or Southeast Portland that previously held one single-family home can today legally support a primary residence plus an ADU plus a duplex on the same parcel, often without a Conditional Use Permit. Pre-application conferences with BDS are the cheapest way to confirm what your specific lot will accommodate.
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