Texas Property Code - PROP § 82.052. Unit Boundaries

(1) if walls, floors, or ceilings are designated as boundaries of a unit, then all lath, furring, wallboard, plasterboard, plaster, paneling, tiles, wallpaper, paint, finished flooring, and any other materials constituting part of the finished surfaces are a part of the unit, and all other portions of the walls, floors, or ceilings are a part of the common elements;

(2) if any chute, flue, duct, wire, conduit, bearing wall, bearing column, or any other fixture is partially within and partially outside the designated boundaries of a unit, then the portion serving only that unit is a limited common element allocated solely to that unit, and the portion serving more than one unit or the common elements is a part of the general common elements;

(3) subject to Subdivision (2), the spaces, interior partitions, and other fixtures and improvements within the boundaries of a unit are a part of the unit; and

(4) shutters, awnings, window boxes, doorsteps, stoops, porches, balconies, patios, and exterior doors and windows or other fixtures designed to serve a single unit, but located outside the unit's boundaries, are limited common elements allocated exclusively to that unit.