Actually, there is a respectable argument to be made for Heidi's position.  The argument goes along the lines that when significant changes take place regarding the relevant characteristics or property rights, the result is a new "subject property."  I don't have my Dictionary of Real Estate available, but I'd be surprised if there is a definition of "subject property."  Common sense says it's the property being appraised.  So if I'm appraising a 1 acre parcel that's been split off a 640 acre parcel, what is my "subject property?"  There are now two new properties.  The old "subject property" no longer exists. What if the entire 640 acre parcel changed hands a year prior to the split?