The subjects above ground GLA contains two bedrooms and one bathroom. The lower level, a partially finished basement, contains a game room and three bedrooms. Due to rolling and sloped topography in the area, basements are not necessarily uncommon. The typical basement, however, in the subject community is usually finished, and most often used as everyday living area by the typical owner. The subjects basement is only partially finished (still having brick and wood paneled walls, indoor/outdoor carpeting, etc). The basement is a footprint of the upper level. COUNTY ASSESSOR'S field card says the subjects basement is the "lower level" and counts/taxes it as Above Ground Living Area. The lower level, however, does have walls below grade and partially finished, as noted above. Long story, not so short...the owners are "appealing" because of the difference between me and county. I know the county is wrong, maybe its getting late, or maybe I'm just getting old, but I just cant find an actual above ground GLA or basement definition and wondering for some input...to satisfy a silly homeowner. Thanks in advance.