Wow! This is still so much fun after being away for years to come back to the forum just to correct errant posters! The poster you replied to was correct. The attorney needs to be informed about appraiser services. There is no need to either testify regarding the prior appraisal report, "redo" any market value service, or "appraisal" (An appraisal is an opinion of value). Because the issue is regarding market rents, not market value. So the well informed appraiser could see opportunity for a new assignment thereby avoiding all problems regarding the prior appraisal services. So no, nobody has to "insist that it's a new appraisal" at all. More, the attorney being properly advised, most likely needs a different effective date than that of the prior appraisal report. It should be an easy matter to show the attorney the superior advantages a new service would bring to them and their client, which would be many. The original poster, if interested in litigation work, should first be researching and learning about engagement contracts for appraiser litigation work before accepting assignments for such things. I would also very much recommend a serious study of the USPAP and state administrative rules through a lens of litigation, and the interviewing of appraisers that routinely do such work prior to proceeding.