It is too complicated to list in a FAQ! We utilize a proprietary relational database program that is in common use for taxation purposes. Just the sketching manual for the program is 81 pages long! Many, many data points are entered, including location, build-ability, sizes, quality of construction, depreciation, amenities, outbuildings, etc. Then elements are priced out using various mathematical equations resulting in a total that should be a rough approximation of market value. The real question is whether the final total is in the ballpark of market value.