Commercial Permit

How Do I Apply?

Please visit the Building Construction Permit section of our Citizenserve Citizen Access Portal to apply online.

When is a Commercial Permit Required?

A commercial permit is required for any work requiring a permit on property that is zoned commercial.

Types of Commercial Permits

  • Occupancy: Occupancy permits are required for all commercial and industrial uses when conducting any type of business inside or outside a building and where any of the following conditions occur:
    • A change of use, tenancy, ownership
    • A structure or space is occupied for any commercial, public or private activity which requires a County license
    • A structure is enlarged, altered or remodeled
  • Construction: a commercial construction permit is required when building a new commercial structure
  • Alterations: A commercial alteration permit is required when altering a commercial structure
  • Additions: A commercial addition permit is required when adding onto a commercial structure
  • Electrical Upgrades: a commercial electrical upgrade permit is required for changes in the electrical system of a commercial structure. 
  • Mechanical Upgrades: a commercial mechanical upgrade permit is required for changes in the mechanical system of a commercial structure. This includes water heaters.
  • Solar Panels: a commercial solar panel permit is required when adding solar panels to a commercial structure.
  • Plumbing Upgrades: a commercial plumbing upgrade permit is required for changes in the plumbing system of a commercial structure.
  • Foundation: a commercial foundation permit is required when building a new foundation for a proposed commercial structure (with the intent finishing construction of the structure at a later date)

What Will I Need to Submit?

  • Building plans (pdf format preferred) showing footing/foundation detail, framing member sizes, header sizes, door and window location and sizes, truss or rafter design, flooring detail, and any electrical or plumbing. Also include floor plan, wall cut detail, elevations, and any applicable stair details.
    • When electric is included, an electrical permit is required regardless of the size of the structure. The minimum service to be installed is: 1 (one) GFI receptacle, 1 (one) light with wall switch, and every man door requires an interior switch and exterior light. 
  • For new construction and additions, contact Planning & Zoning for information on zoning and/or conditional use permit requirements as well as information regarding required site plans.

Fees & Plan Review

Building Permit Fees (PDF)

The plan review process typically takes about 10 working days. When the permit is ready, you will be notified via email that the permit is ready for pick up as well as the final amount of the permit fee.

Building permit fees are based on cost of construction. At the time of application, you will provide us with your estimated cost of construction and our plan reviewers will calculate an estimated cost of construction per ICC Building Safety Journal. The higher of these two estimates will be multiplied by 0.73%; this amount, or the minimum permit amount, whichever is higher, is the building permit fee that will be charged. There may be other fees associated with your permit, such as floodplain permit fees, land disturbance fees, and other fees as applicable.


At least one inspection will be required. When the permit is issued, the necessary inspections required will be listed on your permit card. At the inspector's discretion, some inspections may not be applicable to the particular permit in question. The inspector will note those inspections are "N/A" at a later date.

Inspections must be called into the office by 3 p.m. the business day prior to your requested inspection date. To schedule your inspection, call 636-949-7345. If it is necessary to cancel or change your inspection, please do so as soon as possible. Also, please remember to post your permit so that it is visible from the street.


Please contact the St. Charles County Building and Code Enforcement Division at 636-949-7345 or