St. Peters, MO Building Safety: Building Permits (2026)

St. Peters adopts the 2021 International Building Code by ordinance and then rewrites section 105.2 in full under Section 505.040. Rather than a broad handyman exemption, the City lists specific, narrow no-permit categories: one-story detached accessory structures used as tool sheds, playhouses and similar uses capped at 120 square feet; fences (governed instead under Chapter 405 Zoning and Subdivision Regulations); oil derricks; retaining walls 4 feet or less in height measured footing to top of wall, unless they hold back a surcharge or Class I, II or IIIA liquids; water tanks on grade of 5,000 gallons or less with a height-to-diameter ratio no greater than 2:1; finish work like painting and cabinetry; temporary stage sets; small prefabricated above-ground pools under 24 inches deep and 5,000 gallons; agricultural shade structures; playground swings at one- and two-family homes; certain window awnings; and low fixtures and racks.

The section is explicit that an exemption from the permit requirement never authorizes work that otherwise violates the code or any city ordinance. Once a permit is required, Section 505.040 item 8 (109.2) ties issuance to payment of the fees in Appendix A, and item 5 (107.1) requires construction documents submitted electronically, signed and sealed by a Missouri-licensed architect or engineer, unless the Building Official waives that for minor work. Multi-unit residential permit applications of four units or fewer must also include written verification that a fire sprinkler system was offered to the purchaser before contract, per item 7 (107.2.1.90).