The Cost Approach. One of the three classic methods of valuing commercial real property is the cost approach. In the cost approach, an appraiser values the value of the land and then adds what it would cost to build a new, roughly identical structure. Unless the building is truly unique, and the sole way to replace it would be by rebuilding it, appraisers de-emphasize the cost approach, finding the 2 other appraisal methods more appropriate. It is the primary approach for “specialty” properties – a building designed for a unique use. For example, a purpose built structure like a synagogue or church. Next: the Market Approach.