Regulations on defects in multi-family housing are stipulated by two positive laws: the Act on Ownership and Management of Condominium Buildings and the Multi-Family Housing Management Act. However, the characteristics and purpose of these two laws differ. The Multi-Family Housing Management Act is a public law securing the constitutional rights to housing, which includes administrative laws on the construction of housing (e.g., the Housing Construction Promotion Act) and those related to the management of housing (e.g., the Housing Act and the Multi-Family Housing Management Act). However, the Act on Ownership and Management of Condominium Buildings is a private law merely focusing on the property rights of condominium owners. Therefore, the stipulations of these two positive laws regarding defects in multi-family housing also differ in many aspects, such as the types of defects, standings to claim repair, distribution of responsibility, and statutory limitations. However, the legal aspect remains ambiguous, despite the gap being narrowed through several rounds of enactment and amendment to positive laws. In particular, the meaning of the project implementer's defect repair responsibility, which must be understood from a public law perspective, has been considerably ambiguous. Consequently, for defects in multi-family housing, the focus is merely on monetary compensation for defects, which is a matter of private law, rather than on the implementation of defect repair itself, which is a matter of public law. Accordingly, this study examines the problems related to the repair of defects in multi-family housing by analyzing the history of these positive laws, their detailed stipulations, and the differences in defect warranty liability. Based on these analyses, this study attempts to identify and suggest solutions to overcome these issues.