Deck Permit in St. Louis, MO (2026)

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.

Verified from official St. Louis sources — Last checked April 2026

Quick Facts for St. Louis

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

Do You Need a Deck Permit in St. Louis?

Permit Exemption

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.

St. Louis-Specific Deck Rules

All decks/porches require a permit — no height or size exemption
Historic properties require additional approval for all exterior work including decks
Flood area construction requires a Floodway Development Permit regardless of building code requirements
$25 application fee is non-refundable, paid at time of filing
Permit fee paid only after all approvals received
All permit fees are non-refundable once paid
Frost line depth: 36 inches

How to Get a Deck Permit in St. Louis

1

Check if your deck needs a permit

Review the exemption criteria above. If your deck exceeds any threshold, a permit is required.

2

Prepare your plans

You'll need a site plan, deck dimensions, framing details, and footing specifications. Check St. Louis's specific documentation requirements.

3

Submit your application

Apply through St. Louis Online Permit Application . Pay the permit fee at submission.

4

Build and schedule inspections

Once approved, post your permit visibly and schedule required inspections (typically footing, framing, and final).

Official St. Louis Resources

St. Louis Online Permit Application — Apply for Permits Online Fee Schedule
Transparency note: The following items could not be verified from official city sources and should be confirmed directly: Standard processing time — not published on website.

Estimate Your Deck Cost

Get an instant cost estimate for your deck project in St. Louis.

Deck Cost Calculator

Sources

https://www.stlouis-mo.gov/government/departments/public-safety/building/permits/building-permits/residential-construction.cfmhttps://www.stlouis-mo.gov/government/departments/public-safety/building/permits/building-permits/residential-permit-criteria.cfmhttps://www.stlouis-mo.gov/government/departments/public-safety/building/building-codes.cfm

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.