Sammamish, WA Accessory Structures: Carport Rules (2026)

Sammamish does not publish a carport-specific ordinance; carports are governed as residential accessory structures, the same category as detached garages, sheds, and similar ancillary buildings. The accessory-structures handout states the Municipal Code does not require a building permit for an accessory structure that is on a site free of critical areas or their buffers, is no more than 200 square feet and no more than 12 feet in height, and is used for storage - but most carports will exceed those thresholds or involve attachment to the home and will need a permit. Development standards, cited to SMC 21.04.030.C, set maximum height and minimum setbacks by zone: R-1 allows 35 ft height with 20 ft front, 10 ft rear, 10 ft side; R-4/R-6 allow 35 ft with 15 ft front, 10 ft rear, 10 ft side; R-8 allows 35 ft with 10 ft front, rear, and side; and R-12/R-18 allow 60 ft with 10 ft front, 5 ft rear, 5 ft side. Properties on a major street have a 30-foot minimum front setback in any zone. Rear and side setbacks can be reduced to 5 feet with a recorded adjoining-owner agreement per SMC 21.04.030.C.19. Confirm your zoning, setbacks, and permit needs with the Sammamish Permit Center.