Dictionary of Real Estate Terms: extraordinary assumption
extraordinary assumption
an assumption within an appraisal that is so essential that the value opinion would be erroneous if the assumption proved to be false. Compare with hypothetical condition.
Example: An appraisal of a proposed housing subdivision was based on the extraordinary assumption that it would sell approximately 100 developed lots per year. If the absorption rate proves to be invalid, the value opinion of the appraisal is also invalid.

