A zero net adjustment does not mean the comparable is identical to the subject. The signed amounts cancel, but the underlying differences remain. Positive $10,000 plus negative $10,000 equals $0 net. The gross adjustment, which adds the magnitudes, is $20,000.

For example, a comparable sold for $250,000. Applying those two adjustments leaves an adjusted price of $250,000. Its net adjustment is 0% of the sale price, but the gross adjustment is $20,000 / $250,000 x 100 = 8%. These are different measures of the same calculation.

Keep the individual lines on your worksheet even when the total is zero. The example uses invented numbers and is not an appraisal of a property. Try the worked sales-comparison adjustment problems for another calculation.