Under the measuring standard mentioned previously, below-grade living area is calculated separately from above-grade living area.  This does not mean that appraisers are not attributing value to finished basements, but are considering them as a separate feature.  Just as the cost to build these two areas is often significantly different, their current market value may also be significantly different.  Separating them in an analysis helps identify the relevance and dollar value of this difference.  Combining the size of these areas, as many real estate agents and brokers are now doing, not only misrepresents the home, but also can result in low value estimates throughout that market area if not identified and corrected.