So it would appear that (a) no one has posted either of the FAQ's, and that (b) most see this as a black and white issue - IF there is a 2nd lot, and if that lot is severable, then it MUST be excess land, which is just not the case. First to the FAQ (at least the one that has more meat) 223 - to use the 20/21 version (since we have only 7 days remaining of the 18/19 cycle). The question is (and I summarize), lender wants a MV appraisal on a property with two separate legal lots, and wants them appraised as though they were one legal lot; intended use is mortgage lending. Question (not paraphrased): "May this assignment be completed treating these two lots as if they were one legal lot with the highest and best use as one legal lot?" Response (not paraphrased): "Yes. However, complying with the lender’s request will require use of a hypothetical condition. If the client is a federally regulated financial institution, the client may also need an “as-is” appraisal. If the appraisal were based on a hypothetical condition (i.e., market value of the subject as if it were a single lot), and if necessary for credible results, the appraiser would have to develop an opinion of highest and best use of the hypothetical parcel. If this leads to the conclusion that the highest and best use would be subdivision into two or more lots, the appraiser must perform the appraisal recognizing that potential use and may need to perform a subdivision analysis to reach a credible opinion of the highest and best use of the hypothetical parcel."
Couple of points: (1) the fact that there are two separate lots does not absolutely imply that there are two different H&B uses (e.g. that there is excess land). Determination of whether or not there are separate H&B is the job of the appraiser, who may, OR MAY NOT, conclude that the vacant parcel is excess land. (2) IF the appraiser determines that the 2nd lot is NOT excess land, then the guidance is to invoke a HC (namely that the appraiser is valuing the property as if it were one single lot).
To J's point, if her determination is that the 2nd lot does not have a separate H&B, then the guidance is that she can invoke a HC, and appraise the property 'as if it were one lot'. To the point of (most) others on the post, if the determination is that the 2nd lot does have a separate H&B, then, per the guidance, the appraiser may need to perform a subdivision analysis to reach a credible opinion of the highest and best use of the hypothetical parcel (which may, or may not, require competence that the appraiser engaged in the original assignment may possess).
IMO