a ceiling or part of a ceiling that is lower than the primary ceiling structure. A furdown is often constructed to enclose ducts or pipe that cannot be installed in the ceiling framing spaces and must be installed below the standard ceiling level. Also called "Furred Ceiling", "Furred Down Ceiling" and "Drop Ceiling". Fur Down Chases are built down into space generally occupy the upper portion of hallways, run
along walls, and/or cut across open living which creates lowered ceiling.