Renton, WA Accessory Structures: Carport Rules (2026)

Renton Municipal Code 4-2-110 (residential development standards) treats carports as accessory structures subject to the same rules as detached garages and pavilions. Carports exceeding 200 square feet require a building permit under RMC 4-5-060 and the Washington State Residential Code. Setbacks: 5 feet from side and rear property lines, 20 feet from front property line (carports typically cannot encroach into front yard setbacks except in narrow cases where primary dwelling setback is also 20 feet). Maximum height is 15 feet to the peak for single-story structures. Carports must have at least one open side to be classified as a carport rather than a garage (fully enclosed structures trigger different requirements and different setback allowances). Lot coverage limits in each residential zone (R-8, R-6, R-4, etc.) include carports. A carport cannot block or reduce required off-street parking spaces for the dwelling. Design standards under RMC 4-2-115 require carports to match the primary dwelling in roof pitch, color, and materials in many zones. HOAs may impose additional aesthetic rules. Tent or canopy style carports are generally treated as temporary structures; if left up more than 180 days many cities treat them as permanent and require permits.