“In recent decades, Canadian courts have adopted the equitable concept of unjust enrichment inter alia as the basis for remedying the injustice that occurs where one person makes a substantial contribution to the property of another person without compensation. The doctrine has been applied to a variety of situations, from claims for payments made under mistake to claims arising from conjugal relationships. While courts have not been adverse to applying the concept of unjust enrichment in new circumstances, they have insisted on adhering to the fundamental principles which have long underlain the equitable doctrine of unjust enrichment. As stated by La Forest J.A. (as he then was) in White v. Central Trust Co. (1984), 1984 CanLII 3002 (NB CA), 54 N.B.R. (2d) 293, at p. 309 “… the well recognized categories of unjust enrichment must be regarded as clear examples of the more general principle that transcends them”.
The basic notions are simple enough. An action for unjust enrichment arises when three elements are satisfied: (1) an enrichment; (2) a corresponding deprivation; and (3) the absence of a juristic reason for the enrichment. These proven, the action is established and the right to claim relief made out. At this point, a second doctrinal concern arises: the nature of the remedy. “Unjust enrichment” in equity permitted a number of remedies, depending on the circumstances. One was a payment for services rendered on the basis of quantum meruit or quantum valebat. Another equitable remedy, available traditionally where one person was possessed of legal title to property in which another had an interest, was the constructive trust. While the first remedy to be considered was a monetary award, the Canadian jurisprudence recognized that in some cases it might be insufficient. This may occur, to quote La Forest J. in Lac Minerals Ltd. v. International Corona Resources Ltd., 1989 CanLII 34 (SCC), [1989] 2 S.C.R. 574, at p. 678, “if there is reason to grant to the plaintiff the additional rights that flow from recognition of a right of property”. Or to quote Dickson J., as he then was, in Pettkus v. Becker, 1980 CanLII 22 (SCC), [1980] 2 S.C.R. 834, at p. 852, where there is a “contribution [to the property] sufficiently substantial and direct as to entitle [the plaintiff] to a portion of the profits realized upon sale of [the property].” In other words, the remedy of constructive trust arises, where monetary damages are inadequate and where there is a link between the contribution that founds the action and the property in which the constructive trust is claimed.”