Accessory Structures in Portland, OR (2026)
2 verified accessory structures rules for Portland, Oregon, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Portland caps accessory dwelling units at 800 square feet or 75% of the primary home's living area, whichever is smaller, and requires a 40-foot front setback or placement behind the main house's rear wall.
Portland ADU Permit Requirements
Some RestrictionsPortland City Code § 33.205.040
1. Maximum size. The living area of the accessory dwelling unit may be no more than 75 percent of the living area of the primary dwelling unit or 800 square feet of living area, whichever is less. This maximum size standard does not apply when the basement of a primary dwelling unit is converted to an accessory dwelling unit and the primary dwelling unit has been on the site for at least 5 year...
Shed & Carport Rules
Portland caps detached sheds and other covered accessory structures at 20 feet tall, holds them to standard building setbacks unless they qualify for a small-structure exception, and limits total accessory building coverage to 20 percent of the lot.
Portland Shed Height, Setback and Coverage Rules
Some RestrictionsPortland City Code § 33.110.245(C)
Detached covered accessory structures are items such as garages, carports, greenhouses, artist's studios, guest houses, accessory dwelling units, storage buildings, wood sheds, water collection cisterns, and covered decks or patios that are not connected to the primary structure... 1. Height. The maximum height allowed for all detached covered accessory structures and connected covered accessor...
Looking for Multnomah County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Portland city rules.
Accessory Structures in Multnomah County →