Bellevue, WA Accessory Structures: Carport Rules (2026)

In Bellevue, a carport is a roofed structure open on two or more sides used for vehicle storage and is regulated as a detached accessory structure under LUC 20.20.125 when not attached to the primary dwelling. Unlike small sheds, carports typically require a building permit because they exceed 200 sq ft and involve structural roof framing subject to snow and wind loads under the Washington State Building Code (BCC Title 23). Front and side setbacks must match the primary residence for the underlying zone (R-1 through R-30), with a 5-foot minimum rear setback. Carports must be placed at least 10 feet from any street right-of-way, access easement, or private road. Detached accessory structures in total cannot exceed 10 percent of lot coverage, and the carport also counts against the total lot coverage maximum. Attached carports follow the dwelling setback and count as part of the primary structure footprint. Review by Development Services is required, and design must address stormwater runoff for impervious surface increases.