....error in errors of magnitude whose accummulated total equals what? In appraising there are sorta two parts data and analysis. I have found that horrible preparation with negligent thought can end with a confirming market value justified by a later examination. But by definition, appraisal is a process which includes certain available efforts and informations whose accomplishment satisfies the requirements necessary to meet the definition. A person might be able to blink twice and arrive at a accurate market value, but they would have violated the aspect of process in the appraisal. Again they might assume factors, such as : zoning, size, utility, condition, etc. and still get a result of a supportable figure of market value. But they would have disregarded their obligation to secure adequate data in fufilling their responsibility. In short, you can do it wrong and something turn out alright.
Appraisers travel between fact and judgement. The appraisal process requires the
sufficent aggregration of the first to eliminate as much as possible of the later. Your appraiser's misses in the facts you have named may be offset value-wise in other parts of the analysis resulting in no net effect on the resulting value dollar figure. But you know that some of the facts are wrong. That is why you have to view the appraisal in total. And I would caution the effect of any square footage figures verified through local assessors whose accuracy varies. A further example, a 5% error in condition which tends more toward judgement could be offset by a square footage fact. This directly relates to my earlier statement that the facts and the individual effects can offset each other with a net of nothing to the figures. But the industry's requirement for proper and sufficent facts to be verified and gathered would support the general public's(your...) confidence in the effects of the total report. If for no other reason than that you know the signer did not initially inspect the property and signed that he did, this fact destroys the following trust you were entitled to receive from the appraiser and his report. The ink of the report carries little weight . . . . . . . . . . best to all.............rs