Been reading some of these comments and some things needs noting regarding why clients order a 2055 "drive-by" in the first place. The first, a pre- foreclosure, is obvious. The client knows that the homeowner will not let in the appraiser. Once they foreclose and get the owner out, they will order a full inspection to get a handle on the value based upon actual condition.
For mortgage/HELOC lenders, a 2055 is ordered when there is low risk. The borrower has to have excellent credit and the LTV needs to be so low that it is not considered a significant risk. This is only dome with a desktop underwriting software system. Lenders cannot order a drive-by to "hide something". Not only is it illegal, it is dumb. If a borrower says, "I need a HELOC because I ripped the inside of my house apart and now I need money", there is no way that the bank will say, "ok, we will order a drive-by so the appraiser won't see it". That is just as much a myth as all bankers being big fat white guys in 3 piece suits smoking a cigar.
Finally, lenders do not order 2055s to save on costs. Remember, the appraisal is a "pass through" fee, which means that lenders are forbidden from charging the borrower more than what the fee actually is. Therefore, they couldn't care less about the fee. They order 2055s because their desktop underwriting system says they can to save time and ease the process. However, the key word is "can". Lenders can overwrite the system and upgrade to a full 1004 for any reason they wish. Therefore, if you get to the house and the owner comes out and asks you to come in the house and see all of the upgrades he did, then the loan officer did a horrible job in the application process. I have encountered this and told the owner, "tell you what, I will let the bank know you did a lot of renovations and you want (me) to take that into consideration. They will probably call for a full appraisal". That way, I will be paid for a full and thorough inspection that I feel comfortable with and the owner gets the true value of the house. Everybody happy.