Do I Need a Permit to Build a Deck?
Short answer
For most decks, yes. The model code (IRC R105.2) only exempts decks that are 200 sq ft or less, under 30 inches above grade, not attached to the house, and not serving the required exit door. Attached or elevated decks always need a permit.
Usually exempt (no building permit)
- Freestanding decks ≤200 sq ft, with the walking surface less than 30 in. above grade at any point within 3 ft, not attached to the dwelling and not serving the required egress door
Permit required
- Any deck attached to the house (ledger connections are a leading failure point — this is the rule inspectors care most about)
- Any deck 30 in. or more above grade — guards (36 in. min) and stair rails become mandatory
- Decks over 200 sq ft, and roofed or screened decks (those are additions)
What trips people up
- Footing depth must reach below frost depth — varies by county and is listed on BuildSpec jurisdiction pages where verified
- Hot-tub decks need engineering for the concentrated load
- Stairs, guard spacing (4-inch sphere rule), and lateral-load connectors are the most common correction items
How to apply
Submit a framing plan (joist size/spacing, beam spans, footing sizes, ledger detail) plus a site plan. Many cities publish prescriptive deck guides based on DCA 6 — following one speeds approval dramatically.
Check your jurisdiction: exemption thresholds are from the 2021 IRC (R105.2) as adopted by most states — your city or county may amend them. Find your local building department, adopted codes, and online permit portal on the BuildSpec permit pages.