Abstract
Subsurface property rights come into focus when transport and infrastructure
tunnels are required to service urban settlement. This article investigates the
vertical extent of property in this context. It discusses common law property
theory, examines relevant case law and shows how other jurisdictions have
legislated for subsurface uses. It explores what may legitimately be
considered private and what public, and where an appropriate boundary may
lie. It finds that, just as the upper airspace is considered open for public
navigation, free of any rights claimed by a surface proprietor, subsurface
space below the depth of reasonable use by a surface proprietor should also
be considered public space. This would facilitate the Crown’s ability to
develop underground space for transport and infrastructure without the need
to negotiate with and compensate surface property owners.