Do I Need a Permit to Build a Deck in Utah?
Quick Answer
Yes — unless it's a small ground-level platform under 200 sq ft.
When a Permit Is Required
Utah cities require a deck permit for: decks over 200 square feet, decks more than 30 inches above grade, any deck attached to the house via a ledger board, and decks with structural modifications. A small freestanding platform under 200 sq ft and under 30 inches high may be exempt — but check with your city.
Footings and Frost Line
Deck footings in Utah must extend below the frost line — typically 30 inches along the Wasatch Front, deeper in mountain areas. This is one of the most common inspection points. Footings that are too shallow will fail inspection.
Guards and Railings
Guards are required when the deck surface is 30 inches or more above grade. Minimum guard height is 36 inches for residential decks (42 inches for commercial). Baluster spacing must be less than 4 inches — the classic 'sphere test' (a 4-inch sphere should not pass through).
Ledger Board Attachment
The ledger board (where the deck attaches to the house) is the #1 failure point for decks. Utah inspectors check that ledger boards are attached with lag screws or through-bolts — nails are never acceptable. Proper flashing above the ledger is also required to prevent water damage.
Bottom Line
Most useful decks need a permit. Plan for three inspections (footings, framing, final) and make sure your footings hit 30 inches deep.