Which method is an appraiser using when multiplying the cost per square foot of a comparable structure by the number of square feet in the subject building?

The method described in the question involves multiplying the cost per square foot of a comparable structure by the total square footage of the subject property. This approach is characteristic of the square-foot method, which is widely used in appraisal to estimate the value of a property based on the cost to build similar structures in terms of price per square foot.

In this case, the appraiser is essentially determining a value for the entire property based on a standardized measurement (square footage) and a common cost benchmark (cost per square foot). This method simplifies the appraisal process by allowing appraisers to make quick, comparative analyses based on known data from similar properties.

The other methods mentioned involve different processes or calculations. The unit-in-place method focuses on estimating costs based on the prices of specific components or units of construction rather than a general square footage price. The replacement cost method involves determining how much it would cost to replace the property with a similar one, taking into account depreciation. The quantity survey method involves a detailed assessment of all materials and labor required to construct a property, leading to a much more granular breakdown of costs than simply multiplying square footage by a price per square foot. Thus, the square-foot method is the most accurate choice for the scenario provided.