KD -- very helpful, thanks. Is it true that if I ask the appraiser why a certain comp wasn't used or why a certain adjustment wasn't made, he's obligated to give an explanation?
As I implied before, the appraiser isn't even obligated to pick up the phone.
Okay. What is the ideal protocol for appraising detached condos? Comparables should be:
1) Other detached condos?
2) If not available, then small single-family homes?
3) If not available, then small condominium complexes?
Unfortunately, many people (even in our industry) believe that all properties can be appraised using the same methodology and that the methodology can be expressed in something similar to a flow chart. They can't and it can't.
In general terms, I usually begin an analysis by finding the most similar (or slightly superior) currently available properties. The asking prices of those properties will set a fairly reliable upper limit of value for the subject (the rationale being that no buyer will pay more than they can buy the same thing for). If one can make the assumption that non-condominium ownership is preferred over condominium ownership, then the asking prices of detached homes will set the ceiling for the condominium's value. (Note that these asking prices don't indicate the value of the condominium, they just set an upper limit for that value.)
Conversely, if you were to make the assumption that a detached condominium is more preferable than an attached condominium, recent sales prices of otherwise-similar attached condos would give you an idea of the lower limit of value for your condominium.
So now you've got a range of possible values for your property. The next step is more complicated and depends on several factors, including the width of that range. Lacking comparable sales of identical properties, I'd be inclined to approach the condominium's value from as many directions as possible, including comparisons to all three of the property types you mention. It's impossible to make the call without being there but, generally speaking, the more unique the property, the better it is to correlate different perspectives on value.
This is the way I would approach your appraisal but there are a number of other, equally reasonable methods. Appraising, by nature, is a somewhat subjective art (with no way to test our conclusions) and that's why it's almost impossible to prove that an opinion of value is right or wrong.