¶ 22 Boundary by estoppel is an equitable doctrine designed to prevent fraud and injustice by protecting innocent landowners who reasonably rely on representations by their neighbors regarding their shared boundary lines.Our cases have noted the availability of this theory, but have never delineated its precise elements.See Tripp v. Bagley, 74 Utah 57, 276 P. 912, 918 (1928) (explaining that the doctrine of boundary by estoppel is premised on the protection of the legitimate reliance interests of innocent parties); see. also Douglass v. Rowland, 540 S.W.2d 252, 254 (Tenn.Ct.App. 1976).See, e.g., Staker v. Ainsworth, 785 P.2d 417, 423 n. 4 (Utah 1990) (explaining that boundary by agreement, boundary by estoppel, and boundary by acquiescence are distinct doctrines, but declining to set forth the elements of boundary by estoppel); Hales v. Frakes, 600 P.2d 556, 558 (Utah 1979) (referring to boundary by estoppel merely to explain that "boundary by agreement falls somewhere between adverse possession and estoppel"); Tripp, 276 P. at 918 (noting that a person may only rely on a claim of boundary by estoppel if that person was ignorant of the true boundary).

To establish a claim for equitable estoppel in Tennessee, the party asserting the claim must prove that the opposing party: (1) engaged in conduct which amounts to a false representation or concealment of material facts; (2) knew or expected that the other party would act upon the conduct; and (3) knew or had constructive knowledge as to the actual facts. Thornton v. Higdon, 2008 WL 4693737, *5 (Tenn.Ct.App. Oct. 23, 2008) (citing Douglass v. Rowland, 540 S.W.2d 252, 254 (Tenn.Ct.App. 1976)). The party asserting the claim must also prove that it lacked knowledge and means of knowledge about the truth and relied upon the conduct of the opposing party to its detriment.

When a man has been misled by the untruth propounded by another, and acted to his detriment in reliance upon the misrepresentation, the misleading party will be estopped to show that the true facts are contrary to those he first propounded.Douglass v. Rowland, 540 S.W.2d 252, 254 (Tenn.App. 1976), cert. denied, quoting Duke v. Hopper, 486 S.W.2d 744, 748 (Tenn.App. 1972), cert. denied. The elements of estoppel as related to the party claiming the estoppel are (1) lack of knowledge and of the means of knowledge of the truth as to the facts in question; (2) reliance upon the conduct of the party estopped; and (3) action based thereon of such a character as to change his position prejudicially.

Later, in Gardiner v. Word, 731 S.W.2d 889, 891 (Tenn. 1987), this Court confirmed that Branch required trial courts to be liberal in allowing pretrial motions to amend. See, e.g., Craven v. Lawson, 534 S.W.2d 653, 655 (Tenn. 1976); Walden v. Wylie, 645 S.W.2d 247, 250 (Tenn.Ct.App. 1982); Douglass v. Rowland, 540 S.W.2d 252, 256 (Tenn.Ct.App. 1976); see also Merriman, 599 S.W.2d at 559; cf. Liberty Mut. Ins. Co. v. Taylor, 590 S.W.2d 920, 921 (Tenn. 1979). Although not binding, federal decisions are often helpful in the interpretation of court rules. Rule 15(a) of the Federal Rules of Civil Procedure is almost identical to Rule 15.

Cases since Branch v. Warren have emphasized the liberality with which trial courts should approach the question of whether a pretrial motion to amend should be granted. See, e.g., Craven v. Lawson, 534 S.W.2d 653, 655 (Tenn. 1976); Walden v. Wylie, 645 S.W.2d 247, 250 (Tenn. App. 1982); Douglass v. Rowland, 540 S.W.2d 252, 256 (Tenn. App. 1976); see also Merriman v. Smith, 599 S.W.2d 548, 559 (Tenn. App. 1979); cf. Liberty Mutual Insurance Co. v. Taylor, 590 S.W.2d 920, 921 (Tenn. 1979). There have been no prior Tennessee cases on the question of whether Rule 15.

On appeal, the Sanders request that we resolve this discrepancy and determine that fraud, false representations, or concealment of material facts are not elements of equitable estoppel in nonrealty cases. As support for this proposition, the Sanders cite these cases: Common Wealth Ins. Systems, Inc. v. Kersten, 40 Cal.App.3d 1014, 115 Cal.Rptr. 653 (1974); First Nat'l Bank of Denver v. Ulibarri, 38 Colo. App. 428, 557 P.2d 1221 (1976); Kojro v. Sikorski, 267 A.2d 603 (Del.Super. 1970); Cessna v. Montgomery, 63 Ill.2d 71, 344 N.E.2d 447 (1976), rev'd on other grounds, 104 Ill.2d 261, 84 Ill.Dec. 471, 472 N.E.2d 431 (1984); Dart v. Thompson, 261 Iowa 237, 154 N.W.2d 82 (1967); Pino v. Maplewood Packing Co., 375 A.2d 534 (Me. 1977); Addressograph-Multigraph Corp. v. Zink, 273 Md. 277, 329 A.2d 28 (1974); Watkins v. Central Motor Lines, Inc., 279 N.C. 132, 181 S.E.2d 588 (1971); and Douglass v.Rowland, 540 S.W.2d 252 (Tenn.App. 1976). We determine, however, that such a resolution is unnecessary, for under either theory of equitable estoppel, genuine issues of material fact exist under the facts of this case.

Equitable estoppel may arise not only from written or spoken words or from deeds, but also from the silence of one who is under a duty to speak or an omission to act by one who has a duty to act. Burks v. Elevation Outdoor Advertising, LLC, 220 S.W.3d 478, 491 (Tenn. Ct. App. 2006); Douglass v. Rowland, 540 S.W.2d 252, 254 (Tenn. Ct. App. 1976) (citing Duke v. Hopper, 486 S.W.2d 744, 748 (Tenn. Ct. App. 1972)). As our Supreme Court has stated,

See, e.g., Craven v. Lawson, 534 S.W.2d 653, 655 (Tenn. 1976); Walden v. Wylie, 645 S.W.2d 247, 250 (Tenn. Ct. App. 1982); Douglass v. Rowland, 540 S.W.2d 252, 256 (Tenn. Ct. App. 1976); see also Merriman, 599 S.W.2d at 559; cf. Liberty Mut. Ins. Co. v. Taylor, 590 S.W.2d 920, 921 (Tenn. 1979).

Id. Equitable estoppel may also be demonstrated by the silence of a party when there was a duty to speak. See Douglass v. Rowland, 540 S.W.2d 252, 254 (Tenn.Ct.App. 1976) (citing Duke v. Hopper, 486 S.W.2d 744, 748 (Tenn.Ct.App. 1972)); see also Richardson v. Bristol Land Improvement Co., 1 Tenn. App. 671, 685 (Tenn.Ct.App. 1926). Equitable estoppel applies not only to the party who induced reliance but also to his privies.

Cases since Branch v. Warren have emphasized the liberality with which trial courts should approach the question of whether a motion to amend should be granted. See, e.g., Craven v. Lawson, 534 S.W.2d 653, 655 (Tenn. 1976); Walden v. Wylie, 645 S.W.2d 247, 250 (Tenn.Ct.App. 1982); Douglass v. Rowland, 540 S.W.2d 252, 256 (Tenn.Ct.App. 1976); see also Merriman, 599 S.W.2d at 559; cf.LibertyMutual Insurance Co. v. Taylor, 590 S.W.2d 920, 921 (Tenn. 1979).