What is the term for a life estate that measures its duration by the life of someone other than the life tenant?

A life estate pur autre vie is a specific type of life estate that is measured by the life of another person, known as the measuring life. This means that the duration of the life estate is dependent not on the life tenant but on the life of a third party. For example, if the life tenant has the right to live in a property until another person's death, the estate is considered pur autre vie.

This type of life estate is particularly significant in inheritance situations, where the original owner of the property might want to ensure that another person (the measuring life) is the basis upon which the duration of the property rights is determined. This allows for flexibility in determining who benefits from the property and when those benefits cease, which can be an important consideration in estate planning and property management.

In contrast, a conventional life estate is tied directly to the life tenant themselves, while a remainder interest relates to the future interest that will become possessory upon the termination of a life estate. A reversionary interest refers to the original owner’s right to regain possession of the property after the life estate ends. However, none of these options define the unique relationship and duration conditions present in a life estate pur autre vie.