As much as I hate to admit it, I tend to agree more with JGrant on this thread. It is the same as the mobile home question posed in another thread. For me, it depends on the actual appraisal problem, and I don't find specific terminology to be frivolous or just semantics. If the whole of the task is to determine the contributory value (to the whole) of some improvement(s) situated on a specific tract of land, I agree with the value of the whole minus land value approach. But if a specific tract of land is not in the picture, clearly that can not be a viable option, and it does not reveal the market value of the improvements by themselves. Here, old homes are often offered "to be moved." I am aware of one currently on the market, know of many that were relocated and know of several that were offered and then demolished. I have been partially down the road to acquiring a couple, only to conclude it would only make economic sense to move them to an available (owned) site if I were paid to take them. So, in my view, the "market value" of the improvements alone has little to no relationship with its contributory value as a part of a complete property. The value of the whole minus land value approach ignores the very real and very significant costs involved in getting those improvements to not be a part of a specific, real property. Failing to acknowledge and explain those differences, I think, is typical but inappropriate.