Ratio Decidendi
Proprietary estoppel cannot arise from an agreement that is expressly 'subject to contract'. In commercial contexts, sophisticated parties who knowingly proceed without binding agreement cannot claim they relied on an assurance to their detriment.
Hechos
Cobbe, a property developer, spent time and money obtaining planning permission for land owned by Yeoman's Row on an oral understanding they would sell. The owner then renegotiated the price upward.
Resumen de la sentencia
Lord Scott held that proprietary estoppel was not available. Cobbe knew there was no binding agreement and consciously took the commercial risk. He was awarded a quantum meruit for his services.
Citas clave
"Proprietary estoppel cannot be the route to the acquisition of property rights which the parties intended to be the product of a formal contract."
— Lord Scott
Tratamiento posterior
Narrowed proprietary estoppel in commercial contexts; distinguished from domestic cases like Thorner v Major.