Legal Definitions - ad coelum doctrine

The ad coelum doctrine is a traditional legal principle that asserts a landowner possesses rights not only to the surface of their property but also to the airspace directly above it, extending upwards to the sky, and to the ground beneath it, reaching downwards to the center of the Earth. This doctrine implies ownership of everything found within these vertical boundaries, including immovable resources like solid minerals (e.g., coal, iron ore) located beneath the surface.

However, it's important to note that this doctrine typically does not apply to "fugacious" or migratory resources such as oil and natural gas, which are often governed by different legal principles like the rule of capture.

• Example 1: Overhanging Tree Branches

  A homeowner discovers that a large oak tree from their neighbor's yard has grown significantly, with several branches extending over their property line and casting shade on their garden. Under the ad coelum doctrine, the homeowner has a right to the airspace above their property. The overhanging branches infringe upon this right, even though the tree's trunk is on the neighbor's land. The homeowner might have legal grounds to demand the neighbor trim the branches or, in some jurisdictions, even trim them themselves up to the property line.

• Example 2: Discovery of a Mineral Deposit

  A family owns a large rural plot of land. During a construction project on their property, they discover a significant deposit of granite, a valuable building material, several feet below the surface. The ad coelum doctrine would generally mean that the family, as landowners, owns the granite deposit beneath their property. Since granite is a "hard" or immovable mineral, their ownership extends downwards to include this resource, allowing them to potentially extract or sell the mineral rights.

• Example 3: Unauthorized Underground Infrastructure

  A utility company plans to run a new underground fiber optic cable. To connect two points, the most direct route would involve burying a section of the cable several feet beneath a private residential property without obtaining an easement or permission from the homeowner. Without such authorization, burying the cable beneath the private property would constitute a trespass under the ad coelum doctrine. The homeowner's rights extend downwards, meaning they own the subsurface space where the utility company intends to lay its cable, requiring the company to negotiate for an easement or find an alternative route.