Auburn, WA Accessory Structures: Carport Rules (2026)

Carports in Auburn are regulated as accessory structures under ACC Chapter 18.31 and the 2021 IRC adopted via ACC 15.36. Freestanding open carports of 200 square feet or less and 10 feet or less in height may qualify for the accessory structure permit exemption, provided they are open on at least two sides (enclosures convert them to garages which always require a permit). Setbacks follow underlying zone standards, typically 5 feet from rear and interior side property lines and 10 to 20 feet from front lot lines. Carports attached to the primary dwelling always require a building permit regardless of size because they share structural elements. Carport roofs count as impervious surface under ACC 13.48 stormwater rules and are factored into lot coverage caps (typically 35 to 50 percent by zone). Metal tube-frame carports sold at home improvement stores must be anchored to code and wind-rated for Puget Sound conditions (90 mph design wind). Carports in front yards are restricted in most R zones; check Auburn Community Development for your zone. HOA and CC&R rules often impose stricter restrictions on prefab carports.