Proprietary estoppel

[5] Proprietary estoppel is one of four principal mechanisms to acquire rights over property, seen particularly in the case of land (the others being a contract, an implied trust, and adverse possession).

In Cobbe v Yeoman's Row Management Ltd, a property developer claimed an interest in a group of Knightsbridge flats after his expense in obtaining council planning permission.

Even so, in the House of Lords Mr Cobbe failed in his claim for anything more than the expense (£150,000) of getting the planning, because in this commercial context it was clear that formal deeds were needed for completion of any deal.

By contrast, the factual pattern of estoppels, which often appear something very close to a contract, often seem to warrant more than an award for damages to compensate claimants for the amount of detriment, or loss, as in a tort case.

In Jennings v Rice, Robert Walker LJ tackled the issue by emphasising that the purpose of the court's jurisdiction was to avoid an unconscionable result, and to ensure that a remedy was based on proportionality.

The Court of Appeal resolved, however, that not the full estate, worth £1.285m, but only £200,000 would be awarded in view of the actual detriment incurred by Mr Jennings and the uncertainty of what his assurances really meant.

In Greasley v Cooke , over a house in Riddings , the Court of Appeal affirmed that once an assurance is found, the burden of proof is on the defendant to show that it was not relied up to the claimant's detriment.