A building permit is required for all in-ground, above-ground and on-ground swimming pools, hot tubs and spas. An exception would be a prefabricated portable swimming pool or any other body of water that is less than 18 inches deep.
As part of the required building permit, a (child proof) barrier is required in compliance with section AG105, Appendix G, "Swimming Pools, Spas and Hot Tubs," International Residential Code (IRC). The barrier shall be used to entirely enclose the swimming pool, spa, hot tub, or other contained bodies of water (18 inches or more in depth), meeting the following criteria:
Minimum five foot high non-climbable wall / fence or other permanent non-climbable barrier structure, as measured from the exterior side of the barrier structure.
Walls, fences and all other permanent non-climbable barrier structures shall have no openings through which a spherical object four inches in diameter can pass.
The maximum vertical clearance between grade and the bottom of the barrier shall be two inches measured on the side of the barrier which faces away from the pool area.
Gates shall be self-closing, self-latching, opening outward from the pool area and having self-latching hardware at a height of at least 54 inches measured vertically from the walking surface below.
**Please note: It shall be the responsibility of the swimming pool and/or spa installer to ensure compliance with section AG106, Appendix G, I.R.C., regarding entrapment protection.
If the exterior wall of the residence is part of the barrier, any doors (including doors from the garage) leading into the pool area must be self-closing, self-latching, with self-latching hardware at a height of at least 54 inches measured from the interior door threshold. All window latching hardware must be at least 54 inches from the interior walking surface.
The gate latch release mechanism shall be located on the pool site at least 3 inches below the top of the gate; and the gate (barrier) shall have no openings larger than 1/2 inch when within 18" of the latch release mechanism.