particular activities of the parties. On the model proposed in this chapter, by contrast, decisions as to property rights do not involve the allocation of particular uses or the distribution of particular sticks in a bundle of rights. Indeed, the structure of property law can be understood without examining the positive uses that A may make of A’s thing. In this sense, property law operates in a ‘low cost’ way: it does not identify and allocate particular uses of a resource.20 It has no need to undertake such a complex process as A’s liberties in relation to a particular thing derive simply from the general proposition, broader than and prior to property law, that any action of A (or X) is permitted if it is not wrongful. Property law takes advantage of that proposition in a very efficient way: when complemented by the existence of a prima facie duty, owed to A by the rest of the world, not to interfere deliberately or carelessly with a physical thing, it ensures that A has, in Harris’s words, an ‘openended set of use privileges’ in relation to that thing. Any analysis which assumes that property law seeks to allocate particular sticks in a bundle of rights therefore misses a key point noted by Merrill and Smith,21 and buttressed by a Hohfeldian approach: the varied physical uses that an owner may make of a thing are not protected directly by claim-rights against the right of the world. The potential for A’s physical enjoyment of the thing would exist independently of property law;22 property law need only provide a prima facie duty owed to A by the rest of the world.

2.Setting the Limits of Property Rights

2.1Where A has an undoubted property right

We have seen that, on a Hohfeldian approach to property rights, it is vital to establish the precise nature of the prima facie duty owed by the rest of the world to A, a party with a property right. In this section, we will consider the scope of that duty in cases where A has a clear property right, such as a freehold of land or ownership of a chattel. The argument made in this section is that the duty, which correlates, in somewhat loose terms, to A’s ‘right of exclusion’, consists only of a duty not to deliberately or carelessly interfere with A’s physical thing. It does not extend to a duty not to interfere with particular positive uses that A may wish to make of A’s thing.

a) The ‘right to exclude’

An owner of a thing, whether it is a chattel or land, has a ‘right to exclude’ others from the thing. Some scholars have singled out this right as the most significant

property provides an owner with no powers that he did not have before. An owner’s “use rights” in property turn on whatever natural capacities an owner or his licensees have to exploit “things” that can be objects of property, such capacities being protected by the right of exclusive use for those things he owns.’

where the defendant causally contributed to the partial physical destruction of the claimant’s wharf (in the form of fire damage) by releasing bunkering oil into a harbour. However, because the fire had not been reasonably foreseeable, it was held that the defendant had not been negligent in respect of the fire damage and so was not liable in tort law. The duty owed to an owner of a chattel not to physically interfere with his chattel is not an absolute one: it is therefore most accurately described as a duty not to deliberately or carelessly interfere with the chattel.

Turning to land, the principal torts protecting land, trespass, negligence and nuisance, reflect a similar duty. Again, to give a simple illustration, in Ellis v Loftus the defendant’s horse put its head through the railings that separated the defendant’s land from the claimant’s and bit the claimant’s horse. This crossing of the boundary, albeit by a very short distance, was held to be a trespass, Lord Coleridge saying: ‘ . . . if the defendant place a part of his foot on the plaintiff ’s land unlawfully, it is in law as much a trespass as if he had walked half a mile on it . . . ’27 The defendant’s liability in tort for this physical intrusion demonstrates that he is under a legal duty to the claimant, as are all other third parties, not physically to intrude upon the claimant’s land. Again, this duty is not absolute as the torts have requisite mental states, namely that the interference be deliberate or negligent.28

What constitutes a ‘physical interference’ with land is usually slightly different to a physical interference with a chattel. In the context of chattels, a physical interference typically takes the form of physical contact with the chattel or causing physical damage to it: touching the surface of a painting, punching a hole in it, slashing it with a knife etc. are all clear forms of physical interference. In the context of land, however, the physical ‘interference’ usually takes the form of an intrusion, a physical crossing over the boundary of the claimant’s land. This is due to the ad coelum principle that a freeholder’s right does not just relate to the surface of his land, but to a vertical column extending both upwards and downwards. Take, for instance, Anchor Brewhouse Developments Ltd v Berkley House (Docklands Developments) Ltd,29 where the top of the defendant’s crane, elevated at a great height, oversailed the claimant’s land and this was held to be sufficient for liability in trespass. It cannot really be said that the defendant’s crane made ‘physical contact’ with the claimant’s land. Rather, the physical interference consisted of the defendant’s crossing of the claimant’s boundary. The notion of physically interfering with a claimant’s land by crossing its boundary has been developed and extended by the tort of nuisance. It is difficult to draw a clear distinction between the actions of trespass and nuisance,30 but, broadly speaking, when the thing crossing the boundary of the claimant’s land has, in Merrill’s words, ‘physical dimensions’,

27Ellis v Loftus 1874, 12. See also Lawrence v Obee 1815, Gregory v Piper 1829, and Kynoch v Rowlands 1912.

28Goldman v Hargrave 1967. Although, it is not clear if the defendant need be at fault if he has an ultra-hazardous risk on his land: Rylands v Fletcher 1868, cf. Cambridge Water Co. Ltd v Eastern Counties Leather Plc 1994.

291987. See also Star Energy Weald Basin Limited and another (Respondents) v Bocardo SA (Appellant) 2010.

30See Nolan 2012.