Acquired rights (or droits acquis in French) are a legal principle recognized under Quebec land-use and zoning law. They allow a property owner to continue using a building or property in a way that was legal when it was established, even if subsequent laws or zoning changes would no longer permit that use.
For example, if a duplex was legally built before a zoning change that now only permits single-family homes, the duplex can usually continue to exist and be used as a duplex because it has “acquired rights”.
These rights belong to the property, not the owner. If the property is sold, the new owner generally keeps the same rights.
However, acquired rights can be lost. This may happen if the property’s use changes, if the building is left unused for an extended period of time, or if the building is partially or completely destroyed and not rebuilt according to the applicable rules.