1.7.1. Before and After Rule (Federal Rule). The federal rule—also known as the before and after rule—applies in all appraisals involving partial acquisitions. Under this procedure, the appraiser develops opinions of both the market value before the acquisition and the market value after the acquisition. Requiring this valuation procedure allows acquiring agencies, the Department of Justice, and the courts to calculate a reasonable measure of compensation by deducting the remainder or after value from the larger parcel’s before value. The result is a figure that includes the value of the property acquired as well as any compensable damages and/or direct (special) benefits to the remainder property. It should be noted that these are two separate appraisals within the same assignment requiring the appraiser to perform a new analysis and valuation of the remainder after the taking. It should also be noted that it is improper for an appraiser to develop an opinion of the market value of the larger parcel in the before situation and then deduct the opinion of value of the property acquired together with separately calculated damages to arrive at the value of the remainder. 

If the appraisal is prepared for the Department of Justice, the scope of work will typically not include allocation of the difference between the before and after values into the components of the contributory value of the property acquired and compensable damages to the remainder. However, in assignments for other client agencies the scope of work may include such an allocation in order to assist the agency in meeting their obligations under the Uniform Act.