Multnomah County, OR Accessory Structures: Carport Rules (2026)

Carports in Multnomah County are classified as accessory structures under the Oregon Residential Specialty Code and local zoning. A building permit is required for any carport with a permanent foundation or structural attachment to a primary dwelling. Portland City Code 33.110 sets the following residential limits: 15 ft maximum height in R-5/R-7 zones, 5 ft side/rear setbacks, minimum 10 ft front setback (or match existing garage setback), and must fit within the lot coverage maximum (40% in R-5, 50% in R-2.5). Multnomah County Code 39.4200 uses similar dimensional standards for unincorporated areas. Freestanding carports over 200 sq ft typically require a permit (under 200 sq ft may be exempt per ORSC R105.2). Attached carports must meet the same setback as the dwelling and may require firewall construction if within 5 ft of a property line. Portland Design Overlay (d) zones and Historic Districts (Irvington, Ladd's Addition, Alphabet) have additional design review for visible carports. HOA CC&Rs in planned communities often restrict metal carports. Wind load 115 mph and snow load 25 psf minimum under Oregon Structural Specialty Code. Pre-fabricated carport kits still require permits. Converting a carport to enclosed garage requires a change-of-use building permit.