Utah Boundary by estoppel

To successfully invoke the doctrine of boundary by estoppel, a party must demonstrate:

(1) that the record title owner or her predecessor in interest made an affirmative misstatement that a given line was the true boundary between the neighbors' properties,

(2) that the innocent party took affirmative action in reasonable reliance on this misstatement, and

(3) because of this affirmative action the innocent party would suffer sufficiently substantial injury that it would now be unfair or unreasonable to enforce the record title boundary.

Bahr v. Imus, 2011 UT 19, 250 P.3d 56, 65

(1) First, where a party seeks to establish a property boundary through equitable estoppel, it must establish an affirmative statement by a neighboring landowner regarding the location of a shared boundary. In a boundary dispute case, such representation presumably will be “inconsistent with [a] claim afterwards asserted,” as where the party who made affirmative representations regarding the boundary seeks to establish a different boundary in subsequent litigation.

(2) Second, a party seeking to invoke the doctrine of boundary by estoppel must show that it has engaged in some act in reasonable reliance on the representation of the neighboring property owner. See Tripp, 276 P. at 918. This element requires proof that the party seeking to invoke estoppel has “change[d] his position” on the basis of the misrepresentation of the neighboring landowner. Rautenberg v. Munnis, 108 N.H. 20, 226 A.2d 770, 772 (1967). For reliance to be reasonable, “the truth concerning the facts relied upon by the person claiming the benefit of the estoppel” must have been unknown. Tripp, 276 P. at 918. Thus, parties invoking boundary by estoppel must have been ignorant of the true boundary between their property and the property of their neighbor. As in boundary by acquiescence cases, however, a party need not demonstrate that there was “objective uncertainty” regarding the true location of the boundary, see Staker, 785 P.2d at 423, though a showing of objective uncertainty would certainly reinforce a plaintiff's showing of reasonable reliance.

(3) Third, the final element of boundary by estoppel is proof of injury. See Great Plains Oil & Gas Co. v. Found. Oil Co., 137 Tex. 324, 153 S.W.2d 452, 459 (1941). In evaluating whether a plaintiff's injury is sufficient to sustain an estoppel, the courts should recall the founding rationale of the doctrine—the protection of reasonable reliance interests. See Tripp, 276 P. at 918. Thus, an injury is of sufficient gravity to sustain an estoppel if it is such that it would render it unfair or unreasonable to enforce the record title boundary in the face of that injury. See James H. Backman, The Law of Practical Location of Boundaries and the Need for an Adverse Possession Remedy, 1986 BYU L. Rev. 957, 968.

Bahr v. Imus, 2011 UT 19, 250 P.3d 56, 63