ADU Rules in Portland, OR — 2026 Guide
Check if your Portland property qualifies for an ADU in 20 seconds
Portland ADU Rules at a Glance
Portland is considered ADU-friendly. Here are the key regulations.
- Portland waives system development charges (SDCs) for ADUs — saving $15k–$20k.
- ADUs up to 75% of primary home size or 800 sqft allowed by right.
- OR HB 2001 legalized duplexes and ADUs on all single-family lots statewide.
- No off-street parking required for ADUs.
What ReadyPermit Checks for Portland Properties
Enter any Portland address and get an instant ADU feasibility analysis covering:
Zoning Compliance
Verify your Portland lot is zoned for ADU construction under current OR and local rules.
Setbacks & Coverage
Check required setbacks, lot coverage limits, and height restrictions for your specific parcel.
ADU Size Limits
Calculate the maximum ADU square footage allowed based on your lot size and primary dwelling.
Permit Requirements
Understand what permits and approvals Portland requires before you can break ground.
Flood & Hazard Zones
Identify if your property falls in a flood zone, fire zone, or other hazard overlay.
Lot & Parcel Data
Pull parcel boundaries, lot dimensions, and existing structures from county records.
Check Your Portland Property Free
Enter your address below. In under 20 seconds you will know if your Portland lot qualifies for an ADU — no phone calls, no waiting.
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