Appraisals of real property for condemnation purposes are generally originated by private firms or governmental agencies that have the power to condemn.  Usually the firms or the governmental agencies evaluate a number of appraisal firms based on their experience in the condemnation area since there is specific state and or federal case law that details how an appraisal is to be completed.

When an entire property is being taken a eminent domain assignment is simplified since there is no remainder to consider.  Partial takings of real property can become very complex court cases.  I have been involved in taking cases that required the condemning authority, due to their pressing need for a property, to engage prominent scientists, physicians, marketing experts, psychologists and engineers for their opinions / expert opinion testimony.

For appraisers the best experience in the eminent domain area is having been hired by, and gaining experience from, experience work for both condemning authorities and private individuals or their attorneys.  Being hired for assignment from both sides of eminent domain actions is the only way that an appraiser can gain the experience and perspective necessary to understand the the parties, the issues, report development and the law.

My intial experience in eminent domain came from working as a fee appraiser for a large utility company located in the mid-west.  Their takings crossed through every imaginable property type.  I appraised partial takings from property types including; large vacant tracts of land, agricultural land, single-family residential homesites, developed commercial sites, industrial mining properties and waterfront properties.  A number of them ended up in court and I became their expert witness.

Condemnation cases are focused on the value of the taking and the value of the remainder (before and after the acquisition) which provides a "damage" if any exists, thus condemnation cases are focused on the appraiser and their appraisal.  While many condemnation cases are started after a taking is completed, with the exception of inverse condemnations, few actually go to trial.  Some state governments publish statistics on their cases and I have seen some indicate that as few as 5% to 10% actually go to trial.

From the perspective of the condemnor these cases are generally losers since there are few jurors who will favor a utility or the government over a private party who is being forced to give up a portion of their property.  There is, however, often a battle royale over what the damages are and the cases with huge damage claims are the ones that do get to trial.

From the perspective of the owner condemnation is an intrusion that can force a relocation of a business or effectively destroy a homesite that may have been in a family for generations.  Compensation for sentimental value doesn't happen, there is no way to measure it.  Compensation for aesthetics usually doesn't happen either, again there is no way to put a compensation figure on it.

Appraisers entering the condemnation area have to learn fast and be detail oriented.  If you haven't viewed, photographed and double confirmed each fact about your subject property and your comparable sales you will be staring at it on the witness stand and wondering what on earth you were thinking when you didn't.  When the only person an attorney has to destroy on the stand is an appraiser, they know it is usually going to be a good day in court.         

In my opinion the best expert witness appraisers were those who had several years of appraisal experience and knew the market because they had valued a number of properties in it over time.  Its wasn't the appraiser who provided the most sophisticated presentation with lots of graphs and mathematics who impressed most of the jurors who I polled over the years but the ones who came across as simply being knowledgeable.