Detached Accessory Structures

You Provide 

  • Two complete sets of construction designs.
  • Site survey.
  • Completed Building Permit Application
  • Mechanical, Electrical, and Plumbing permits must be applied for through St. Louis County's Public Works Department 314.615.7156.
  • Detached accessory structures between 200-249 sqft require a building permit.
  • A detached accessory structure over 250 square feet will require:
    • Conditional Accessory Structure Permit.
    • Frost protected footings.
    • Must be within the zoning district's side-yard and rear-yard setbacks.  Visit our Municipal Code for requirements pertaining to accessory structures. 
    • Approval from the Planning & Zoning Commission
  • Click here for Accessory Structure Guide

Call for the following inspections:

  • Footing Inspections
  • Foundation Inspections
  • Framing Inspections: after St. Louis County m.e.p. inspectors have approved their rough inspections.
  • Drywall Inspections: if applicable.
  • Final Inspections: After St. Louis County m.e.p. inspectors have approved their final inspections.
For additional information or further clarification please view our Municipal Code or contact the Public Works Department at