Section 4.6.1.1

4.6.1.1. Larger Parcel Determination.By definition, a partial acquisition involves property that is some part of a unitary holding (the “whole”),729 commonly called the larger parcel or parent tract.730 In a partial acquisition, “[i]t is often difficult . . . to determine what is a distinct and independent tract”—the whole property, comprising the part acquired and the remainder.731 But this determination of the larger parcel is critical for proper consideration of compensable damages and offsetting benefits.732 As discussed in Section 4.3.3, the key factors in determining the larger parcel are (1) unity of use (i.e., highest and best use), (2) unity of ownership, and (3) physical unity (proximity or contiguity). 

Certain aspects of the larger parcel determination merit particular emphasis in partial acquisitions. Appraisers must bear in mind “the distinction between a residue of a tract whose integrity is destroyed [or impaired] by the [acquisition] and what are merely other parcels or holdings of the same owner” that are not part of the remainder for compensation or valuation purposes.733 Also, the availability of replacement property for the parcel acquired must be considered—as reasonable buyers and sellers would do.734 This may be contrary to some state law and practice.735 But in federal acquisitions, failing to consider the availability of replacement property may result, in the words of the Fifth Circuit, in a valuation that “offends any rules relating to the awarding of just compensation for property taken for public use.”736