Why is it important to secure a building permit?

A building permit ensures that your building project is structurally sound, that it complies with the building and zoning codes and more importantly, that the structure is built to ensure the health, safety and welfare of all occupants.

When obtaining a building permit, your proposed project is:

• reviewed for zoning compliance so that the location of the structure is within the setback regulations for your property;
• reviewed by plan reviewers who verify proper materials are used and that the St. Louis County Building Codes are enforced;
• inspected to ensure the building plans are followed and that all St. Louis County Codes are met;
• approved for occupancy by a final inspection and issuance of a Certificate of Use and Occupancy.

Also, per the County Building Code, a building permit is required. If a building permit is not secured, you will be cited with a no permit penalty.

When is a building permit required?

A permit is required for any new construction, additions to existing buildings, structural alterations to an existing building, retaining walls over 2 feet in height and new or replaced plumbing, electrical or mechanical work. However, a building permit is not required for minor repairs, general concrete flat work (residential patios, residential driveways, residential sidewalks) within your property lines, fences less than 6 feet in height, utility sheds 100 square feet or less, or retaining walls under 2 feet in height. For additional information on building permits, read our list of  Work That Does Not Require a Building Permit or Land Disturbance permit or contact our Department at 615-5184 /(TTY 615-3748).

St. Louis County Public Works has four locations to serve all areas of the County. Our main office is in Clayton, and our satellite facilities are located in north, south and west St. Louis County.

When applying for a permit, four sets of all building documents, drawn to scale, are required. Depending on the type of construction, the four sets will include some or all of the following types of plans: a site plan; floor plans; elevation plans; sections and details; electrical, plumbing and mechanical plans; structural calculations and heat gain and loss calculations. If your construction project is located in a municipality, please contact the local city hall for zoning approval and also to verify whether that municipality or St. Louis County Public Works will assist you in the permit application process for your building project.

All construction plans submitted must be sealed by a Missouri licensed architect or engineer. Residential building plans drawn by the homeowner for construction of his/her new residence and plans for miscellaneous residential structures such as decks, garages, etc., which may be drawn by either the home owner or their contractor are the ONLY exception to this requirement. These home owner drawn plans are not required to be sealed by a licensed architect or engineer.

For detailed information on residential building projects, see our series of brochures on residential building permits for a variety of projects.