Buying a home with an ADU in Oregon

Oregon state-level rules buyers should know

• • HB 2001 (2019) requires Oregon cities over 10,000 population to allow duplex/middle-housing — and many extended this to ADUs.
• • Portland legalized ADUs in 2010, so mature ADU stock exists.
• • Maximum size: typically 800–900 sq ft in Portland; varies by city.
• • Owner-occupancy: not required statewide; Portland eliminated its requirement in 2010.
• • Parking: Portland eliminated parking requirements for new ADUs in 2010.

What to check when buying

• ✓ Pull the Portland Bureau of Development Services permit record — Portland's portal is well-organized.
• ✓ Older Portland ADUs (pre-2010) may have grandfathered permits with different rules.
• ✓ Verify whether the unit is on the same parcel or a flag lot — Portland has unique flag-lot rules.
• ✓ Confirm rental-licensing — Portland requires landlord registration.
• ✓ Check height — Portland's ADU height limits vary by zoning code (R5, R2.5, etc.).

Permit info for Oregon cities

The strongest signal of a legitimate ADU is a clean permit history at the city. Use these jurisdictional guides to cross-check what the seller's disclosure tells you.

• Permits in Portland

Related

• Full ADU buying guide
• ADU value analysis
• Verified ADU builders in Oregon
• Portland permit overview
• ADU cost guide