Tex. Health & Safety Code § 757.007

A wall of a building constructed before January 1, 1994, may not be used as part of a pool yard enclosure unless each window in the wall has a latch and unless each window screen on a window in the wall is affixed by a window screen latch, screws, or similar means. This section does not require the installation of window screens. A wall of a building constructed on or after January 1, 1994, may not be used as part of a pool yard enclosure unless each ground floor window in the wall is permanently closed and unable to be opened.