This chapter establishes comprehensive rules for Condominium Ownership, defining it as comprising exclusive rights, common rights, and joint management. It addresses crucial issues like the regulation of parking spaces and outlines the powers of owners’ assemblies and committees. The text provides a comparative legal analysis, examining different terminologies (e.g., apartment ownership, residential ownership) and theoretical frameworks (monism, dualism, tripartite theory) used in jurisdictions such as Germany, Japan, and the United States. It concludes by emphasizing the necessity of this legal institution in modern urban environments, where high-density living necessitates a specialized system to manage complex, three-dimensional neighborly relations.