St. Louis, MO Building Safety: Building Permits (2026)
Key Facts
- Exempt height limit
- 12 inches above grade max
- Must be
- uncovered, no permanent foundation
- Governing provision
- § 25.01.020 (IBC § 105.2, item 25)
- Permits issued by
- Division of Building and Inspection
- Existing-deck repairs
- exempt if non-structural
Summary
A concrete patio slab or ground-level wood deck skips a St. Louis building permit only if it's uncovered, unsupported by a permanent foundation, and no more than 12 inches above grade; anything taller, roofed, or footed needs one.
...concrete patio slabs or wooden patios/decks which rest directly on the ground or a rock base, provided that they are not covered by a roof or canopy, not supported by any type of permanent foundation, and a maximum of twelve inches above adjacent grade;
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 11).
Full Breakdown
St. Louis's Building Code exempts patios and decks from a building permit only if they meet strict criteria: a concrete slab or wood deck resting directly on the ground or a rock base, uncovered by any roof or canopy, unsupported by a permanent foundation, and no more than 12 inches above adjacent grade. Add a roof, build on footings, or raise the surface higher, and the project needs a permit from the Building Division under § 25.01.020, which adopts the amended International Building Code. Minor like-for-like repairs to an existing deck's boards, rails, or stairs stay permit-exempt if they don't touch structural framing.
Violations & Fines
Building a raised, roofed, or foundation-set deck without first pulling a permit violates St. Louis Revised Code § 25.01.030; the building official can issue a stop-work order, and each day of continued work counts as a separate offense.
Frequently Asked Questions
Do I need a permit for a ground-level patio in St. Louis?
What makes a St. Louis deck need a permit?
Sources & Official References
Other rules in St. Louis
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