Is Airspace Property?
October 14, 2025
BY Greg Blue
What rights does an owner of land have in the airspace above the land? The answer to that question has a great deal to do with the degree of control an owner can exert over the aerial activities of others, whether they are aviators, balloonists, trapeze artists, or a contractor whose crane in the adjacent building site occasionally swings over the owner’s house. The answer, however, is murky at best.
An ancient Latin maxim states that whoever owns the ground owns everything upward from it to the heavens (cujus est solum ejus usque ad coelum). It still turns up occasionally in legal arguments, but it’s not treated literally as a principle of law.
Some Canadian case law holds that airspace is not a thing capable of ownership. This does not fit well with the BC Land Title Act, which declares that airspace is “land” and provides for the creation and registration of title to airspace parcels with vertical and horizontal boundaries. The Act also provides that airspace parcels may be transferred, leased and mortgaged, like ordinary lots and condominium units.
In the 20th century, the invention of powered flight and the growth of aviation led courts in Canada, the UK and the US to hold that a landowner’s rights to airspace were limited to as much airspace as was needed for full enjoyment of the land. In other words, only so much airspace as a landowner can occupy or use, such as by constructing a building on the land, planting trees that grow into the airspace, or erecting a utility structure like a radio transmission tower. Courts in all three countries held that the passage of an aircraft over private property at a safe altitude doesn’t amount to trespassing.
There is no comprehensive benchmark for how far vertically upward a landowner’s rights extend, however. One possible benchmark that has some limited support in Canadian and U.S. case law is the minimum altitude at which aircraft are allowed to fly when they are not taking off, landing, on an approach, or engaging in one of several specified low-altitude operations. The Canadian Aviation Regulations specify that flight must take place at a minimum altitude of 1000 feet over a built-up area or an open-air gathering of persons, and 500 feet over open ground. This would be above the amount of airspace that most landowners could occupy or use, but not all. Think of CN Tower.
Whatever the exact nature of the rights that landowners have in airspace, it’s fairly well- established in BC case law as well as in other parts of Canada that landowners do not need to be actively using airspace immediately above their land and the structures on it in order to prevent others from doing so without their permission, as long as they could potentially use the airspace at the height in question.
So how high does a surface owner’s right to control airspace actually extend? The answer is up in the air.
