Building Permits

County Building Permit Process

Building Under ConstructionGeneral Information: 314-615-7156
Search Permits (Citizen Access)

Why Important?

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.

Per St. Louis County Building Code, if a building permit is required and not secured, a "no permit penalty" can be cited.

How To Obtain?

How do I obtain a building permit?

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:

  • site plan
  • floor plans
  • elevation plans
  • sections and details
  • electrical, plumbing and mechanical plans
  • structural calculations
  • 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, including construction plans for a new residence.


Residential building plans for miscellaneous residential structures such as decks, garages, etc., 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 Residential Permits or our series of Residential Brochures for a variety of projects.

For information concerning lead paint abatement on pre-1978 homes, schools and day care centers, click here for Consumers or here for Contractors.

For detailed information on commercial projects, see Commercial Permits.

When Required

A building permit is required to construct, enlarge, alter, reconstruct, or repair most buildings or structures and to construct, enlarge, alter, reconstruct, overlay, or reconfigure a parking lot.

Structures include, but are not limited to, retaining walls, fences, sheds, garages, carports, greenhouses, above-ground tanks, towers, antennas, flag poles, solar arrays, wind turbines, signs, swimming pools, etc. of which the requirement to obtain a permit is usually based on height or size.

Permits are not required for ordinary repairs or qualifying minor work. For detailed specific information on when permits are, or are not required, select When are Permits Required? under Construction & Permits or contact our Department at 314-615-5184.

New Businesses In Existing Buildings 

I want to open a new business in an existing building. Do I need a permit?

I would like to relocate my business into an existing shopping center. Do I need a permit?

Yes. Any time the use or occupancy of a commercial building changes in unincorporated County, a Re-occupancy Permit is required. If any renovations are made, a building permit must be obtained, the work must be inspected and approved by the Department of Public Works; a certificate of occupancy will then be issued.

Out-Of-State Contractors

Out-Of-State Contractors
must register with the Missouri Department of Revenue as a
Transient Employer prior to obtaining a permit.

St Louis County cannot issue a permit to a Transient Employer without documentation confirming registration with the State of Missouri.

Additional Info

For additional information:

  • Call Commercial Occupancy Permit Applications at 314-615-3724
  • Call Commercial Inspections at 314-615-3724.
  • For Residential Re-Occupancy Permits:
    • Call 314-615-7346 (North of 40/64)
    • Call 314-615-4142 (South of 40/64)