I. What is land?
For the purpose of trespass, “land” includes more than the surface of the ground. It can also include buildings, specific parts of buildings, structures attached to land, the airspace needed for the ordinary use and enjoyment of the property, and the subsoil beneath it, as well as items standing on or attached to the land such as trees, plants, vegetables, and standing crops.
(i) Surface and fixtures
Land includes the ground, soil, earth, and any structures permanently affixed to it.
Structures or items affixed to the land (i.e. fixtures), such as doors, windows, or certain machinery, are generally regarded as part of the land, and their unauthorised removal or destruction is a trespass.
Whether an item is a fixture depends on the degree of annexation (i.e. the extent to which the item is physically attached to the land) and the object (or purpose) of the annexation (i.e. whether the item was fixed for the permanent improvement of the land or merely to facilitate its better enjoyment as a chattel). As a general rule, an item resting on the land by its own weight alone is prima facie a chattel, while an item physically attached to the land is prima facie a fixture, though either presumption may be rebutted by the purpose of annexation. In Hong Kong, air conditioners bolted to exterior walls are considered fixtures, whereas units merely resting by their own weight are treated as chattels.
(ii) Airspace
Rights in airspace extend to the height necessary for the ordinary use and enjoyment of the land. Trespass can be committed by overhanging cranes, advertising signs, or cables.
Under section 8(1) of the Civil Aviation Ordinance (Cap. 448), the flight of an aircraft at a reasonable height and in compliance with regulations does not constitute trespass. However, the owner of the aircraft is strictly liable for material loss or damage caused by the aircraft or anything falling from it.
(iii) Subsoil
Ownership of the surface generally includes the strata beneath it, including minerals, unless these have been legally alienated. Land and its subsoil can be divided into horizontal, vertical or other layers; for example, one person may possess the surface for pasture while another possesses the peat or minerals beneath it.
Trespass may be committed by tunnelling under land in the possession of another or by unauthorised mining operations. Unauthorised mining or digging under the surface is a trespass. In Hong Kong, however, all minerals and mineral oils are generally vested in the Government under section 3 of the Mining Ordinance (Cap. 285), and specific licences may allow mining that does not constitute trespass against the surface owner.
(iv) Incorporeal rights and profits à prendre
While trespass to land primarily protects physical (corporeal) property, it also extends to certain incorporeal rights—non-physical property interests in land, such as rights of common, pasture, or fishing.
A profit à prendre is one type of incorporeal right: it is a right to enter another person's land and take some profit from the soil, such as minerals, fish, or timber.
Accordingly, incorporeal rights such as profits à prendre may support a legal action where they are interfered with or disturbed.
