Permit Required? Required
Typical Fee Range $100–$300 Based on the estimated cost of construction with a minimum base fee.
Fee Method Valuation-based

St. Louis issues deck permits for any attached structure, and the thing people most often miss is the footing inspection — the building division must inspect before you pour concrete. Skip that window and you may be asked to excavate to prove the footings are compliant. The upside: St. Louis allows owner-occupants to pull their own permits, so you don't need a contractor just to get the paperwork done on a straightforward DIY deck.

St. Louis Deck Rules

  • Building permit required for all decks attached to a structure.
  • Structural plans showing footing depth, joist size, and beam spans.
  • Footings must reach a minimum depth of 30 inches (frost line).
  • Handrails required for all decks with 3 or more steps.
  • Guardrails must be at least 36 inches high for raised decks.
  • Ledger boards must be through-bolted or lag-screwed to the rim joist.

How the Process Works

1

Prepare Structural Drawings

Create scale drawings showing footing depth (30-inch frost minimum), joist sizing, beam spans, and ledger attachment method. The plan reviewer checks all four.

2

Submit Application

Upload plans via the online portal or apply in person for Express Review. As an owner-occupant, you can pull the permit yourself — no contractor required.

3

Plan Review

Building inspectors review for structural integrity and zoning setbacks. Typical turnaround is 5–10 business days.

4

Permit Issued — Pay Fee

Pay the valuation-based fee to activate the permit. Keep the permit card on site during construction.

5

Inspections

Three required: footing (before pouring concrete — do not miss this), framing, and final. Call for the footing inspection as soon as holes are dug.

Frequently Asked Questions

If the deck is over 50 sq ft and attached to the house, it requires a permit.
St. Louis code requires a 30-inch frost depth.
Yes, as an owner-occupant of a single-family home.