Cuius est solum, eius est usque ad coelum et ad inferos
Cuius est solum, eius est usque ad coelum et ad inferos (Latin for 'whoever owns [the] soil, [it] is theirs all the way [up] to Heaven and [down] to Hell') often appearing without et ad inferos 'and to hell', is a principle of property law, stating that property holders have rights not only to the plot of land itself, but also to the air above and (in the broader formulation) the ground below.
In modern law, this principle is still accepted in limited form, and the rights are divided into air rights above and subsurface rights below. Property holders generally have a right to the space immediately above and below the ground – preventing overhanging parts of neighboring buildings – but do not have rights to control flights far above their property, or subway construction below. In dense urban areas, air rights may be transferable (see transferable development rights) to allow construction of new buildings over existing buildings.
The phrase (in air form) is credited to 13th-century Italian jurist Accursius, and is said to date in common law to the time of Edward I. It was more recently promulgated, in broad form (air above and ground below) by William Blackstone in his influential treatise Commentaries on the Laws of England (1766); see origins, below, for details. This article primarily discusses the applications to air rights.
As the name describes, the principle is that a person who owns a particular piece of land owns everything above and below it as well. Consequently, the owner could prosecute trespass against people who violated the border but never actually touched the soil. As with any other property rights, the owner can sell or lease it to others, or it may be taken or regulated by the state.
For example, suppose three people owned neighboring plots of land. The owners of the plots on the ends want to build a bridge over the center plot connecting their two properties. Even though the bridge would never touch the soil of the owner in the middle, the principle of cuius est solum would allow the middle owner to stop its construction or demand payment for the right to do so.
By the same principle, a person who wants to mine under somebody's land would have to get permission from the owner to do so, even if the mine entrance was on neighboring land.
The phrase, in air form, is credited to the glossator Accursius in the 13th Century. It has been suggested that the principle was brought to England by Accursius's son, Franciscus Accursius, who came to England with Edward I on the latter's return from the crusades. The principle was firmly established in common law by Edward Coke in Bury v. Pope (1587), which gives the first statement in English law of the principle, writing (Liber 1, section 1, page 4, section "Terra" (earth)):
And lastly, the earth hath in law a great extent upwards, not only of water as hath been said, but of aire, and all other things even up to heaven, for cujus est solum ejus est usque ad coelum, as it is holden.
The reporter's note to this case ascribes the maxim to the time of Edward I, which accords with the attribution to Accursius (father and son). Two other cases around 1600 also use the principle, and a number of 19th century cases also apply it.
The phrase appears in Blackstone's Commentaries, Book 2, Chapter 2, p. *18:
Land hath also, in its legal signification, an indefinite extent, upwards as well as downwards. Cujus est solum, ejus est usque ad coelum, is the maxim of the law, upwards; therefore no man may erect any building, or the like, to overhang another's land: and, downwards, whatever is in a direct line between the surface of any land, and the center of the earth, belongs to the owner of the surface; as is every day's experience in the mining countries. So that the word "land" includes not only the face of the earth, but every thing under it, or over it. And therefore if a man grants all his lands, he grants thereby all his mines of metal and other fossils, his woods, his waters, and his houses, as well as his fields and meadows.
This formulation, though it omits the et ad inferos "and to hell" wording, includes that interpretation ("and the center of the earth"). Largely through the influence of Blackstone, this broader formulation became influential in American law. See Sweeney reference for various formulations of the principle in Anglo-American law.
The principle does not occur in classical Roman law. The phrase was used by Accursius in discussion of rights to have burial plots or tombs free from the interference of an overhanging building. In Coke's formulation, he cites three cases involving birds; the circa 1600 cases involve overhanging roofs, while the 19th century cases address diverse topics. The principle attracted increased interest in the 20th century with the development of airplanes occasioning much discussion, particularly in the 1930s, and the development of space travel yielding further discussion in the 1960s; some earlier discussion had also occurred around hot air balloons.
The ad coelum doctrine began to fall into disfavor with the advent of air travel:
After the first hot-air balloon flight in 1783, people began to realize that ad coelum could lead to absurd results. Jurists occasionally invoked aerial-balloon trespass as an example of a trivial injury for which the law wouldn't provide redress, and it appears that no one ever sued a balloonist just for flying over. . . . [E]ven if the balloonists' flights were technically illegal, "the law was out of step with the expectations of the parties, in that neither landowners nor balloonists thought there was anything wrong with overflights"
Although everyone tolerated balloons, the invention of the airplane forced the legal world to seriously rethink the aerial-trespass problem. Most everyone found the old rule undesirable, but people disagreed on how it could be discarded. Adherents of the common-law view that judges "found" the law (in the people's customs or through reason) had to argue either that earlier courts erred in adopting the principle from Roman law (i.e., they argued that this wasn't actually the Romans' rule), or that the earlier rule was narrower in scope than its wording suggested. Legal positivists had an easier argument: if judges just "make" law, then they could now make it one way instead of another. And legal realists could simply predict that judges would modify the law because the facts of cases would persuade them to do so.
In Lord Bernstein of Leigh v Skyviews & General Ltd  QB 479, the Court noted that the phrase was 'colourful', but said that it was well settled in the common law that a land owner had rights in the air immediately above the land, extending in particular to signs overhanging from adjacent properties. The right did not extend though to more than was 'necessary for the ordinary use and enjoyment of the land and structures upon it'. Planes, hot air balloons, and the like, would not commit a tort of trespass by merely passing over a person's property.
In Star Energy Weald Basin Limited and another v Bocardo SA  UKSC 35, the UK Supreme Court (having heard argument that the principle was no longer relevant to land ownership) held that the principle "... still has value in English law as encapsulating, in simple language, a proposition of law which has commanded general acceptance. It is an imperfect guide, as it has ceased to apply to the use of airspace above a height which may interfere with the ordinary user of land [cf Bernstein, above]..." and that "... the owner of the surface is the owner of the strata beneath it, including the minerals that are to be found there, unless there has been an alienation of them by a conveyance, at common law or by statute to someone else".
The property right to air superincumbent to land was confirmed in Kelsen v. Imperial Tobacco Co.  2 QB 334, where a sign erected on a building that overhung the plaintiff's property committed the tort of trespass, even though no harm or nuisance was caused by it. An injunction was granted to the landowner causing the sign to be removed.
low-flying military planes caused the plaintiffs' chickens to "jump up against the side of the chicken house and the walls and burst themselves open and die" . . . The plaintiffs sued the government, arguing that they were entitled to compensation under the takings clause of the Fifth Amendment.
The court's decision, authored by Justice William O. Douglas, could have resolved the case on a narrow ground by simply holding that there was a taking of land because the government's flights affected the land. Justice Douglas did reach that conclusion, but then he went much further and opined on what airspace landowners do and do not own. He wrote that "if the landowner is to have full enjoyment of the land, he must have exclusive control of the immediate reaches of the enveloping atmosphere. Otherwise buildings could not be erected, trees could not be planted, and even fences could not be run" . . . Thus, a landowner "owns at least as much of the space above the ground as he can occupy or use in connection with the land," and invasions of that airspace "are in the same category as invasions of the surface."
With the advent of space technology in the latter half of the twentieth century, the question broadened beyond the extent of the atmosphere. The ownership of property in space has been murky, with strong arguments both for and against. In particular, the making of national territorial claims in outer space and on celestial bodies has been specifically proscribed by the Outer Space Treaty, which was, as of 2012[update], ultimately ratified by all spacefaring nations.
- Air rights
- Airspace, an analogous concept in international law
- Australian mining law
- Chicago Convention on International Civil Aviation
- Energy law
- Mineral rights
- Riparian rights
- Right to light – right to light passing through adjacent air space
- Property Law
- United States v. Causby
- Huebert, Jacob H. Who Owns the Sky?, Mises Institute
- The Straight Dope: Can I declare a "no-flight zone" over my house?
- Harvard Legal Essays, Written in Honor of and Presented to John Henry Beale and Samuel Williston, 1977, Ayer Company Publishers, Incorporated, p. 522, note 8: "He who owns the soil owns it up to the sky." The maxim had no place in the Roman law during its classical period, but is said to have been first used by Accursius of Bologna, a commentator, who flourished in the thirteenth century. It has been suggested that the maxim was introduced into England by the son of Accursius whom Edward I brought with him on his return from the Holy Land and who for many years held high office under the Crown and also was connected with Oxford University. Bouvé, Private Ownership of Airspace, 1 Air Law Rev. 232, 246–248. At any rate, nearly three centuries later the reporter's note to Bury v. Pope, Cro. Eliz. 118 [78 Eng. Rep. 375] (1587) ascribes the maxim to the time of Edward I."
- Clement Lincoln Bouvé, "Private Ownership of Airspace", 1 Air Law Rev. 232, 376 (1930), 246–248
- AERONAUTICS: Sky the Limit?, TIME, August 4, 1930
- “A colourful phrase often upon the lips of lawyers since it was first coined by Accursius in Bologna in the 13th century”, Justice Griffiths, in Baron Bernstein of Leigh v Skyviews and General Ltd  QB 479, quoted in "Max Headroom: Ownership Of Airspace – Can You Reach For The Stars?", Digging the Dirt, Jon Dickins, Monday, 28 February 2011
- Wilkie, Malcolm & Luxton: Q&A: Land Law 2011 and 2012, Oxford University Press, Chapter 2: Definition of Land, p. 5, "Question 1:Cuius est solum, eius est usque ad coelum et ad inferos (the owner of the land owns everything up to the sky and down to the centre of the earth). … Suggested Answer: This maxim, which was coined by Accursius in the thirteenth century, relates to the extent of the ownership enjoyed by the fee simple owner."
- Bury v. Pope, Cro. Eliz. 118 [78 Eng. Rep. 375] (1587), reporter's note
- Schick, F. B. (October 1961). "Space Law and Space Politics". The International and Comparative Law Quarterly 10 (4): 681–706. doi:10.1093/iclqaj/10.4.681.
- (See detailed case history here) SWETLAND v. CURTISS AIRPORTS CORPORATION, 41 F.2d 929 (1930), District Court, N. D. Ohio, E. D., July 7, 1930, p. 5–7 (41 F.2d 934 & 935)
- John G. Sprankling, Owning the Center of the Earth, 55 UCLA L. Rev. 979, 982-83 (2008).
- Edward C. Sweeney, "Adjusting the Conflicting Interests of Landowner and Aviator in Anglo-American Law," 3 Journal of Air Law and Commerce (1932), 355–373. (Cited in Schick, footnote 1)
- ab and ad mean "from" and "to", and are common Latin words; orco, from the Italian underworld god Orcus, refers poetically to the underworld, coelum means "sky, heaven", and usque means "continuously, without break"
- Huebert, Jacob H. (2011-04-18) Who Owns the Sky?, Mises Institute
- United States v. Causby, 328 U.S. 256 (1946)
- Simberg, Rand (Fall 2012). "Property Rights in Space". The New Atlantis (37): 20–31. Retrieved 2012-12-14.