(a) Gross floor area means all space, wall to wall, including recessed entries not to exceed 5 sq. ft. and areas under built-in vanities and similar furniture. Where the ceiling height is less than that specified in §3280.104, the floor area under such ceilings shall not be included. Floor area of closets shall not be included in the gross floor area.

(b) Habitable room means a room or enclosed floor space arranged for living, eating, food preparation, or sleeping purposes not including bathrooms, foyers, hallways, and other accessory floor space.

(c) Laundry area means an area containing or designed to contain a laundry tray, clothes washer and/or clothes dryer.