St. Louis, MO Accessory Structures: Shed Rules (2026)

Under St. Louis Revised Code Title 25 (Building Code) §25.32.030, detached accessory structures (sheds, playhouses, small storage buildings) with a floor area of 200 sq ft or less and no electrical, plumbing, or mechanical systems are exempt from the Building Permit requirement. Zoning compliance under Title 26 §26.52 (Accessory Uses and Structures) still applies regardless of size. Setback requirements: minimum 3 ft from rear and side property lines in single-family and two-family districts, and no placement allowed in the front yard (forward of the principal dwelling's front building line). Maximum height 12 ft at peak for accessory structures in residential districts, and total accessory structure coverage cannot exceed 30% of the rear yard. Sheds larger than 200 sq ft require a Building Permit through the Building Division (314-622-3313), plus a Zoning Clearance confirming setback and coverage compliance. Electric service to a shed requires a separate Electrical Permit under Title 25 regardless of shed size. Historic districts require Cultural Resources Office review for any new accessory structure.