Why must the same measurement standard be applied to the subject and to the comparables?

Correct Answer

B) Mixed standards corrupt the size adjustment

Why this is correct: The core principle is that adjustments in the sales comparison approach must reflect genuine market differences in property characteristics, not differences in measurement technique. If the subject is measured using one standard (e.g., ANSI) and a comparable using another (e.g., local custom), the calculated size difference is a mix of actual size and methodological variance. This corrupts the size adjustment, which is often the largest and most influential adjustment in the grid, making the final value opinion unreliable. Consistency in the measurement standard is paramount. Why the other choices are wrong: The claim that 'Regulators audit measurement methods each year' is incorrect; while regulators may review work, annual audits of measurement methods are not a universal requirement driving this rule. The statement 'Only one standard is legal in most states' is false; multiple recognized standards (like ANSI) are permissible, but the appraiser must apply one consistently. The idea that 'Collectors are trained in a single method' is irrelevant; data collectors' training does not dictate the appraisal principle of internal consistency for a specific assignment. Exam tip: Remember, the key is internal consistency within your appraisal. You can choose any recognized standard, but you must use the same one for all properties in your analysis to ensure adjustments are pure.