I think you need to clarify why they want to appraise a portion of land.
You only need to know what the purpose of the appraisal is. I could ask an appraiser to come value 1 SF of land in my front yard. I would tell him that it is to establish the market value of the property. You don't need to know why to the extent that you have mentioned. We aren't mortgage brokers and governmental lending restrictions have no bearing on the SOW, unless it is one of the client's conditions.
If the lender only loans on a half acre; the answer should be no.
--Irrelevant
If you are appraising it for condemnation purposes, via eminent domain and you have a map of it; you will need to determine if there are any severance damages to the rest of the parcel.
--Not if it is outside of the SOW
Perhaps the government wants a piece and you need to find out if the taking of the portion (cut out) affects the rest of the parcel.
--Maybe
If this is a lot line adjustment where an adjacent owner is selling off a portion to another adjacent owner and it is legally permissible they need a map of it and you need to do a before and after appraisal before the bank will release that portion of the "cut out."
--Again, not if it is not within the SOW
Ask to talk to the owner and find out why they need a cut out valued
--They could come back and simply say for internal reasons, or because because, or for estate planning. Honestly, I think you overthought it a bit Amy, some of this is sage advice, but you don't have to know that the owner intends on determining the market value of the "cut out" because he wants to sell it to his second cousin Joe, who is going to build a home with a red barn, gravel driveway, and fence the perimeter for his two dogs and one cat that he is going to have around to kill any potential mice.
the answer for something like this is just not so simple and frankly if they are trying to get around lender guidelines because they want to sell a loan; it is not reason enough.
--Irrelevant
Moreover, some lenders will not lend on properties with a lot of land because they want to avoid the risk associated with land value; getting an appraiser to break these rules is not ethical. You need to know where the "cut out" is and what it is for. It should be for a valid, ethical reason.
--Not if the subject of the appraisal is clearly stated within the LOE and SOW