A permit is required for pools more than 24 inches deep or having a surface area of more than 250 square feet. All pools must be enclosed by fencing. The enclosure shall extend a minimum of four feet above the ground and be constructed so as to prohibit the passage of a sphere larger than four inches in diameter through any opening or under the fence. Fence gates must be self-latching and self-closing with latches placed at least four feet above the ground. Specifications for above and below ground installation may be found in the Building Ordinance.