Background and Purpose: In societies that are developing and transitioning towards modernity, similar to Iran, one of the most important issues that the people of these The rules of ownership and residence in traditional housing are similar to modern housing, i.e. apartments. Therefore, the purpose of the current research is to explore and research a part of this problem, that is, to know how the will of the partners affects the common parts of the apartment.
Materials and Methods: This article is descriptive and analytical. Materials and data are also qualitative and data collection was used to collect materials and data.
Ethical Considerations: In this article, the originality of the texts, honesty and trustworthiness are respected.
Findings: The findings showed that the will of the partners in the possession of common parts is different in different assumptions and situations, and the influence of the will of the partners is undeniable, and possession without the permission of all the partners is prohibited and causes liability.
Result: The effect of the will of the partners in the possession of the common parts of the apartment in Iranian and French laws are very similar to each other. In the laws of both countries, the conventional occupation of apartment facilities requires some kind of general representation from other owners, and any unconventional occupation requires special representation in the form of concluding a contract with other owners and obtaining their consent.