It's up in the air: air rights in modern development.

• Author: Schwartz, Martin A.

Romans gave us architectural marvels, funny looking numbers, and the concept of property rights in airspace under the doctrine "culus est solum, cus est usque ad coelum" translated as "[to] whomsoever the soil belongs, he owns also to the sky." (1) The doctrine endows a landowner with a private property right in the airspace, upward to an indefinite extent, above the land. It was incorporated into both English and American common law, appearing in Edward Coke's commentaries in the 17th century and William Blackstone's commentaries in the 18th century. (2)

Although this doctrine may have worked well in the age of Robin Hood, the unlimited right of ownership of airspace above private property created a problem with the advent of commercial aviation in the early 20th century. In response, Congress limited the scope of landowners' airspace rights to an upper limit of private ownership in order to allow for air travel. The enactment of the Air Commerce Act of 1926 created a "public right of freedom of transit in air commerce" through the navigable airspace of the United States. Navigable airspace is defined as airspace above the minimum altitudes of flight and is designated a nationally shared common area for modern flight. Generally speaking, the navigable airspace consists of airspace above an elevation of 500 feet from ground level.

Currently, although 49 U.S.C. [section] 40103(1) states that the "United States Government has exclusive sovereignty of air space of the United States," subsection 2 recognizes public use of airspace only above navigable airspace, thereby retaining private ownership below navigable airspace.

Because the statutory limitation on ownership of airspace conflicted with the common law rights in unlimited ownership of airspace, a potential taking issue arose as a result of this early federal legislation. This issue came before the Supreme Court in 1946 in United States v. Causby, 328 U.S. 256 (1946). The main issue in this case involved a low flight path of U.S. bombers and other aircraft over plaintiff's property. The flight path and size of the aircraft caused intense noise and vibrations resulting in death to plaintiff's chickens and mental distress to plaintiff. Justice Douglas, however, writing for the Court, stated that the ad coelum doctrine "has no place in the modern world. The air is a public highway, as Congress have declared." (3) The Court noted, however, that landowners still maintain a property interest in the nonnavigable airspace above their land.

The common law doctrine of ownership of airspace has been limited to allow for air travel, but the concept of a landowner's ownership of airspace above the surface of owned land below navigable airspace remains well established. The ownership and use of air rights are significant in today's society in the context of view easements, solar access easements, flight path easements, and development rights in the nonnavigable airspace above an owner's land. It is important to note, however, that while one may own the nonnavigable airspace above one's property, local zoning and land use regulations may make it impossible or expensive to utilize such airspace in development.

Horizontal Subdivision of Airspace

Most development situations involve an integrated ownership of fee interest in the underlying land, the building, and the airspace occupied by the building. However, is it possible to transfer airspace and own airspace separately and apart from the ownership of the surface of the land? Some courts held that one must own underlying surface land in order to own the overlying airspace. (4)

Today, the law is...