The Numerus Clausus Principle in Contemporary Australian Property Law

The numerus clausus principle is one of key metaprinciples of the property law of common law systems. It refers to a 'closed list ', or a set menu, of finite types of property rights. In land law, it limits the number to less than a dozen comprising the estates, the servitudes and the security interests. The rationale that underpins this metaprinciple is the idea that by simplifying the range of rights, it is easier for prospective purchasers to discover how rights over land have been fragmented. This article examines the contemporary application of the numerus clausus principle in recent Australian case law. It argues that while historically it may have operated to impose an optimal standardisation on the number ofproperty rights, it now unduly restricts the development of property law. The basic reason for this is that cheap and eflcient registration systems have substantially removed the problem the numerus clausus principle was originally meant to solve. These systems not only make it comparatively easy to discover idiosyncratic packages of rights over land, but it forces those who create them to register if they are to be enforceable against third parties.