The last type of depreciation is called external, which is a loss in value caused by something outside of the property, such as an economic depression or proximity to a contamination site. So, in essence, you have replacement cost, new, less depreciation, to give you a depreciated cost amount. To this amount is added the estimated value of the land. Typically, each appraisal report should have a short introduction or methodology section explaining the who, what, when, where and why of an appraisal report. When reading the appraisal report, make sure it is consistent.
Consistency is key to a quality report.