Don't be pissed when they use caves as comps. It is what it is and you made a decision to build a cave like dwelling in the side of a hill and now want other tax payers to subsidize your decision to build a home that doesn't have wide spread market support but want some sort of concession from the taxing authorities. Sad to say, but if you don't save enough in energy savings etc to justify your choice in life below grade then its not the markets problem or the local taxing authority's responsibility to cover your lack of insight or foresight. If you feel you made no mistakes in your choice of design etc. why would you be pleading for treatment different than any body else? Made your bed, now lie in it. As noted, your cost of construction may be higher that typical 2 x 4 construction. There is no reason that the taxing authority can not take this into consideration and tax you accordingly.
My, my, such hostility....
We are not pissed, just trying to use the tools the system gives us, much the same as a defense attorney in a criminal case. I doubt you would want your attorney to not do his/her best just because they do not agree with you.
Your comments directly support my position. Without ever seeing the house you label it a cave, when in fact it has available natural light in every room and is much brighter than any of our neighbors. The problem is not with the house or its design, it is with the perception of the average buyer when they hear the term 'earth sheltered'. Believe me, we have heard all the comments: cave, dank, dark, claustrophobic, hobbit house, etc. But when people actually tour the house, as many have, they are amazed at how light it is and how much sense it makes. We have never had any negative comments after such a tour. But it is human nature to be suspicious of that which they do not know or understand.
The perception by the general public is what sets market value, and if that perception is negative, justified or not, it will have a negative effect on the value. I believe this exactly what the appraisal principal of obsolescence is intended to address. I do not believe there is anywhere in the appraiser code that has room for fault, ignorance, genius or any other such concepts. A proper appraisal should be based upon comps, not emotion. If there are no comps the code gives tools to address the issue. Those are the tools we will use. Hopefully, at some point the average buyer will be more aware and ignorance or misguided prejudice will not affect value.
If you allow your personal philosophy to impact your appraisals maybe you should be sure to notify your prospective clients so they can be properly prepared for the result.