Except as provided by the declaration (1) if walls, floors, or ceilings are designated as boundaries of a unit, the lath, furring, wallboard, plasterboard, plaster, paneling, tiles, wallpaper, paint, finished flooring, and other materials constituting a part of the finished surfaces of the walls, floors, or ceilings 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 a chute, flue, duct, wire, conduit, bearing wall, bearing column, or other fixture lies partially within and partially outside the designated boundaries of a unit, the portion serving only the unit is a limited common element allocated solely to the unit, and any portion serving more than one unit or a portion of the common elements is a part of the common elements;
(3) subject to (2) of this section, spaces, interior partitions, and other fixtures and improvements within the boundaries of a unit are a part of the unit;
(4) shutters, awnings, window boxes, doorsteps, stoops, porches, decks, balconies, patios, and each exterior door and window or other fixture designed to serve a single unit that is located outside the boundaries of the unit, are limited common elements allocated exclusively to the unit.