Jeff
Of course you can appraise a property you have never seen if that is what the specifics of the case merit. Defining the appraisal problem is the key element that allows you to decide the requisite scope of work.
If you are asked to do a retrospective appraisal for court testimony for an attorney who has a client whose home was torn down by an overly aggresive city contractor three years ago and a new ball park now sits on the site, there is nothing in USPAP to prevent the appraiser who is competent in such work from providing the requested appraisal.
The issue of competency in such matters is a matter of discerning judgement, and in recognizing that the data collection will be difficult, many assumptions, or even hypotheticals will be needed. So long as you have adequately defined the appraisal problem and the related scope of work (client, use, users, date, assumptions, relevant property characteristics, etc), gather the appropriate data, competently analyze the data, and provide logic conclusions from the data, you would be OK.
Will your report be as reliable (or credible) as the appraiser who was actually in the house the week before it was torn down? All other things being equal but assuming each appraiser did an equally competent job for their particular assignment conditions, one would not expect your appraisal (value conclusions) to have the same degree of reliability or credibleness as the other appraisers, but you could still do the work in accordance with USPAP.
The key issue is what would other appraisers, experienced in the same or similar assignments, would expect for you to do in the data collection and analysis phase of the assignment. Clearly the biggest problem is getting a
good idea of the physical characteristics of the subject, and the related problem of finding comparable sales. In this scenario, tax records, old MLS records, photos and discussions with the property owners and neighbors, obtaining prior apprasials from banks, etc, etc.
In my opinion, the actual question you posed is similar in concept. What the client has done is agreed with some limiting conditions which require you to make some assumptions. If you have sufficient data that they have provided and it is consistent with other information that you have available, you can develop an appropriate value conclusion. When communicating the appraisal, you need to make the assumptions clear so that other intended users (not just the loan officer) understand the limitations. If the information you have is inconsistent (say GLA or year built is very different), you can still do the appraisal but you would need to disclose the issues. Better yet, another call to the lender. At some point in time, the increasing limiting conditions would make the report unreliable for the use of type of lending proposed by the client, that is a professional decision that you have to make after discussion with the client.
Regards
Tom Hildebrandt GAA