Nociar v Cound 2014 BCSC 1343 contains a passage that outlines the modern approach to the criteria re proprietary estoppel.
A claim arose as to the right of a son to live on a farm owned by his father who developed dementia and then died.
His half sister attempted to evict him from the property but the court found the sound had a licence to occupy the property given to him by the deceased, and the principle of proprietary estoppel applied so as the half sister did not have the right to revoke his licence to live there.
“Following the decision in Taylor Fashions Ltd. v. Liverpool Victoria Trustees Co. Ltd.,  1 All E.R. 897 (Ch. D.), appellate courts in British Columbia and elsewhere in Canada have adopted instead the so-called modern approach, based on a broader and more flexible set of principles: for example, Tretheway-Edge Dyking District v. Coniagas Ranches Ltd., 2003 BCCA 197 and Erickson v. Jones, 2008 BCCA 379.
 In the recent decision in Clarke v. Johnson, 2014 ONCA 237 at para. 52, the Court provided a helpful summary of the principles governing the modern approach to proprietary estoppel:
˗ proprietary estoppel may form the basis of a cause of action;
˗ it is not essential that the five probanda be satisfied;
˗ rather, three elements must be established:
(i) the owner of the land induces, encourages or allows the claimant to believe that he has or will enjoy some right or benefit over the property;
(ii) in reliance upon his belief, the claimant acts to his detriment to the knowledge of the owner; and
(iii) the owner then seeks to take unconscionable advantage of the claimant by denying him the right or benefit which he expected to receive;
˗ detriment includes expenditures but countervailing benefits may also be considered;
˗ reliance may be express or inferred;
˗ if an equity arises, the court has a broad discretion to fashion an appropriate remedy.
 The Court also cited this useful passage from the pioneering Taylor Fashions decision at p. 913.
I am not at all convinced that it is desirable or possible to lay down hard and fast rules which seek to dictate, in every combination of circumstances, the considerations which will persuade the court that a departure by the acquiescing party from the previously supposed state of law or fact is so unconscionable that a court of equity will interfere. Nor, in my judgment, do the authorities support so inflexible an approach.