Not unethical, but likely unproductive. I found out a long time ago that I can impeach the assessor's work much easier than I can "appraise" for tax relief. The fact is that the Assessor and the B of Equalization are biased against appraisals. The IAAO even teaches a course to assessor on how to impeach YOUR reports...Do You Think It Is Etical To Do An General Purpose Appraisal On Your Property For A Tax Appeal