Everything you need to know about getting a deck permit in St. Louis: fees, requirements, exemptions, and direct links to the Building Division, Department of Public Safety.
Permit Fees
$25 application fee + valuation-based permit fee. $0-$1,000 project: $19 permit fee ($44 total). $1,001-$2,000: $23 ($48 total). $2,001-$3,000: $30 ($55 total). Over $3,000: $10 per $1,000 of estimated cost.
A $5,000 deck: $25 application + $50 permit fee = $75 total. A $10,000 deck: $25 + $100 = $125 total.
Processing Time
Not published. Multiple city agencies review the application. Permit is issued after all approvals received and permit fee is paid.
Apply Online
Yes — via St. Louis Online Permit Application
Building Code
2018 International Residential Code (IRC) — Ordinance 70795, adopted August 1, 2018. 2018 IBC — Ordinance 70794.
Contact: (314) 622-3313 | Room 425, City Hall, 1200 Market Street, St. Louis, MO 63103
All decks and porches require a permit in St. Louis — no size or height exemption. Retaining walls ≤18 inches are exempt but decks are not.
If your deck does NOT meet all exemption criteria, you must obtain a permit before construction. Building without a required permit can result in fines, stop-work orders, and required demolition.
Review the exemption criteria above. If your deck exceeds any threshold, a permit is required.
You'll need a site plan, deck dimensions, framing details, and footing specifications. Check St. Louis's specific documentation requirements.
Apply through St. Louis Online Permit Application . Pay the permit fee at submission.
Once approved, post your permit visibly and schedule required inspections (typically footing, framing, and final).
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Sources
Data verified April 2026. Fees, processing times, and requirements are subject to change. Always confirm current information with St. Louis's Building Division, Department of Public Safety.