I received and accepted an order for a single family 2055 exterior appraisal. Did the research to find out what I could on the property, and went by the house to do the exterior inspection. I noted an almost identical home located next door, accessible by what looked like an alley. When I got back to the office and started the report I noticed on the assessor data sheet that there were three units on this property. So I contacted the assessor's office and they told me that there is a single family home and a duplex, both located on the same parcel. I asked if this was legal and was told it is legal, but non-conforming. I asked if it could be divided possibly by a sale, and was told that because a split would landlock the duplex, it would not be approved. So I called the lender. Asked, "Did you know there is a duplex on this property?" Oh yeah, they forgot to tell me that. But they only want me to appraise the single family dwelling. Can that be done, especially on a 2055? As this was a new lender, one I'd never heard of before, that called me out of the blue, something about the situation didn't sit well with me, and I declined the order. But the question remains, could an appraisal be completed that way, if your order from the lender says appraise just the one family portion, disclosing what I know about the property? Seems to me there's got to be some sort of USPAP violation in there. I just want to make sure I have it right for the future. Thanks for your input!