Statistics on basements are presented in terms of the number of housing units located in structures built with a basement, on a concrete slab, or in another way. Basement is defined as enclosed space accessible to the occupants beneath all or part of a structure and of sufficient depth so that an adult can walk upright, Units built on 8 concrete slab have no basement and no crawl space or air space below the first floor. The category other includes units in structures resting on a foundation of posts, those built directly on the ground, and those having only crawl space under the building to provide ventilation or accessibility for service or repairs.