Seattle, WA Accessory Structures: Carport Rules (2026)

Under SMC 23.44.016, parking, garages, and carports in Neighborhood Residential zones may not be located in the required front yard (20 feet from the front property line) and may not be located in a required side yard abutting a street, or within the first 10 feet of a required rear yard abutting a street. Standard side-yard setbacks of 5 feet apply. Carports are permitted in the rear portion of the lot (within the last 25 feet of lot depth, or the rear 20% of the lot, whichever is less). Per SMC 23.44.014, the combined footprint of the house and accessory structures may cover no more than 35% of the lot on lots of 5,000 sq ft or more, or 1,000 sq ft plus 15% on smaller lots; in RSL (Residential Small Lot) zones the cap is 50%. Accessory structures may cover no more than 40% of the required rear yard. Carports that are 750 sq ft or smaller, single-story, and have beam spans of 14 feet or less may use a Subject-to-Field-Inspection permit through SDCI; larger or more complex projects require an Addition/Alteration permit. Up to three vehicles may be parked outdoors on a single-family lot.