Residential Deck Requirements

Required Drawings

  1. Site plan (can be copy of your plat of survey) showing relation of new deck to existing structures and property lines.
  2. Detail drawings showing dimensions, joist and beam sizes, pier and post locations and sizes, stair, handrail, and guardrail details.

Permit applications without these required drawings shall not be accepted.


Concrete piers of 8 inches minimum diameter and 42 inches below grade are required for all decks 2 feet or more above grade. Minimum post size shall be 4X4, unless the deck is 5 feet or more above grade, in which case the minimum post size shall be 6X6. Posts must be connected to piers by a metal post anchor fastener or shall extend to the bottom of the concrete pier.


Deck framing shall be designed to carry a load of not less than 40 pounds per square foot. Ledger boards shall be fastened to the

existing structure by means of minimum 3/8-inch lag screws at not more than 24 inches on center. Metal joist hangers shall be used for attachment of joists to ledger boards and beams. All metal hangers, fasteners, plates, anchors, etc. shall be rust resistant. All lumber must be treated or naturally decay resistant. No framing members shall rest directly on earth.

Guardrails & Handrails

Decks with a finish floor 30 inches or more above grade must have a minimum 36-inch high guardrail. If built-in seating is provided at the perimeter of the deck, the 36-inch guardrail height is measured from the seat. All guard and handrails shall be constructed such that the vertical spindles are spaced such that a 4-inch sphere will not pass.


All stairs shall be constructed to be in conformance with the requirements of the 2019 International Residential Code. Generally, this means stairs shall be a minimum of 36 inches wide and the maximum riser height shall not exceed 7 3/4-inches in height. Stairs with 2 or more risers must have a handrail, and stairs 30 inches or more in height shall have a handrail on both sides of the stair. Stairs exceeding 10 feet in vertical height must have a minimum 36 inches by 36 inches landing at the mid-point.

Please call the Building Department at 630-552-8425 with any questions.