In most cases, you’ll need to acquire a permit before the construction of your new deck can start. Building codes clearly state that the construction of decks raised 30 inches above ground level need permits, but the guidelines on decks below 30 inches are less clear-cut. There are exemptions in the International Residential Code for custom decks less than 30 inches high, provided their total area doesn’t exceed 200 square feet, and they’re not attached to the home or serve as the exit door for a house.