acessão

Acessão is a legal concept that refers to the mode of acquiring ownership of things to which something else has been united or incorporated, either naturally or artificially. In essence, it is the right of the owner of a thing to acquire what is added to it or united with it. This concept is prevalent in civil law systems.

There are several types of acessão. Natural acessão occurs when things are united without human intervention. Examples include the formation of new land through the gradual deposition of soil by a river (alluvion) or the separation of a piece of land by a sudden flood (avulsion). Artificial acessão, on the other hand, involves the incorporation of things by human activity. This includes the construction of buildings or other structures on land owned by another person, or the planting of crops by someone on another's property.

The rules governing acessão aim to resolve potential disputes over ownership when two or more properties or materials become joined. Generally, the principle followed is that the owner of the principal thing acquires what is united to it, provided that separation would cause damage or loss of value. The specific application and outcome of acessão cases can vary significantly depending on the jurisdiction and the particular circumstances of the case, often involving principles of good faith and compensation for the party whose property or labor has been incorporated.