Due to the high value that it placed upon the ownership of land, the common law traditionally was wary of intervening if the plaintiff non-contractually improved the defendant’s land. For the most part, liability was imposed only if the landowner acted unconscionably according to the doctrine of proprietary estoppel. Recently, however, Canadian courts have expanded the scope of relief in two respects. First, the test for proprietary estoppel has been revised and relaxed. Second, the cause of action in unjust enrichment is now widely employed as an alternative source of liability. While neither development is necessarily wrong, the implications of those changes have received too little attention. A sensitive balance must be struck between the interests of worthy claimants and the interests of innocent landowners
