Proprietary estoppels can be used as a defence rather than a remedy as it is another method whereby a person may receive the equitable interest that they deserve without the appropriate formalities

Proprietary estoppels can be used as a defence rather than a remedy as it is another method whereby a person may receive the equitable interest that they deserve without the appropriate formalities. Proprietary estoppel comprises three main elements. Firstly, the owner of the land will give an assurance to the claimant that he/she will have some rights over the land. Secondly, the claimant must belief that he/she would receive interest in the property. Thirdly, the claimant must have to be acted to his detriment. This detriment has to be substantial and this is illustrated in the case of Gillet v Holt.
Constructive trusts describes the circumstances in which property is subjected to a trust by operation of law. This was illustrated in the case of Paragon Finance V DB Thackerer stating if it can be Irrational for the owner of a property to proclaim his beneficial interest, constructive trust will arise by law. Constructive trusts do not need to be in writing as they are exempted from the operation of Law Property Act 1925 s 53(1) (b), by s 53(2). Mere denial of an informal arrangement or understanding is of itself generally insufficient, since equity will not assist a volunteer. The owner should be unjustly enriched or the claimant must have acted to their detriment.

The development of the doctrine of Proprietary estoppel can be seen through the way courts approach this doctrine and it can be seen in early cases such as Ramsden v Dyson that the courts initially adopted a broad approach in establishing this doctrine. Since a successful claim in proprietary estoppel could result in the creation of interest in land that affects estate owner and future purchasers and transferee of land, it is not surprising the conditions have become stricter. These conditions were first codified by Fry LJ in Willmott v Barber where he identified the five probanda of proprietary estoppel which is quite big of a hurdle for claimants. As a reflection of modern condition, the five probanda by Fry LJ have been largely abandoned and a more modern approach which is much more flexible is introduced. According to Oliver J in Taylor Fashions v Liverpool Victoria Trustees, a claimant will be able to establish an estoppel if they can prove an assurance, reliance and detriment in circumstances in which it would be unconscionable to deny a remedy to the claimant. This modern approach provided more effective remedy as the requirement needed to make a claim has significantly been ‘watered down’. This shows that the doctrine of PE has changed in the sense that it had become more flexible with less difficult hurdles for claimants. It was established in Jennings v Rice that these four features should not be looked at separately but must be looked at ‘in the round’. The House of Lords in Thorner v Majors reiterated that a holistic approach should adopted when establishing proprietary estoppel.
In order to claim under this doctrine, there must be some kind of assurance made by the owner of the land to the claimant that either he can abstain from exercising his strict legal rights over his own land or that the claimant might have some present or future right or use over the land. Mostly, in cases the assurance will be as to some specific property right over the land. However, in the case of Thorner v Major, this is not always necessary. On the facts, there was an implied understanding that David was going to inherit the land. The COA in determining whether implied understanding can amount to assurance held that PE could not be given since assurance has to be based on clear promise. The HOL reversed the decision of the COA and Lord Walker explained that assurance is determined depending on context and awarded PE in favour of David and the farm was granted to him. Furthermore in Ramsden v Dyson, it was established that a representation can be made by conduct even by remaining silent. Assurance that have been taken to be enough can be seen in the case of Gillett v Holt where Mr Holt said he wanted to Geoffrey to run the farm which he saw as being a ‘permanent arrangement’.
As discussed above “assurance” may be entirely informal, but whatever form it takes it os ssential that it produces an effect on the claimant. Reliance may be hard to prove and a claimant can show reliance through change in conduct. The court of appeal in Greasly v Cooke held that, if clear assurance have been made and detriment has been suffered, it is permissible to assume that reliance has occurred. Similarly in Wayling v Jones, the court of appeal only looked for a ‘sufficient link’ between the assurance made and the detriment incurred by the plaintiff, and the burden would be on the defendant to show that there was no reliance. The crucial point seems to be that there will be no reliance only when it can be shown that the claimant would have incurred detriment completely irrespective of the defendant’s conduct as can be seen in the case of Orgee v Orgee. However, there are some cases such as Campbell v Griffin which shows that a detriment which is not caused by defendant’s conduct may also be considered reliance. Hence, it can be said that the existence of reliance is critically dependant on the peculiar facts of each cases which cannot be discounted merely because of family or emotional ties that might otherwise explain a course of action.

In order to establish Doctrine of Proprietary Estoppel the claimant must prove that he has suffered detriment in reliance on assurance and it can be in any form either minimal or trivial. An example of detriment is to work for low pay or no pay as can be seen in the case of Gillett v Holt. As Campbell v Griffin and Jennings v Rice show, it is not necessary that the detriment be related to land at all as long as there is detrimental reliance which makes retraction of assurance unconscionable. In Jennings v Rice, the COA held that proportionality was essential between expectation and detriment in deciding how to satisfy equity based on PE. It should be noted that detriment alone is insufficient as seen in Taylor v Dickens, where the plaintiff worked for a number of years without pay with the expectation the he would inherit from the deceased. In the case, the deceased changed her will and left it to another and the plaintiff could not claim proprietary estoppel as there was no assurance despite there being detriment. Although this may seem harsh, it remains the case that an unencouraged detriment is not sufficient for the purpose of this doctrine. The case of Lloyd v Dugdale cleared this doubt as it made it clear that the detriment must be incurred by the person to whom the assurance is made.