This thesis aims to examine the application and enforcement mechanism of court decisions in civil cases involving the demolition of permanent buildings, with a specific focus on the High Court Decision Number 285/PDT/2023/PT SBY. The central legal issue explored is how the court implements fundamental legal principles such as legal certainty, justice, good faith, and simplicity of judicial proceedings in delivering its verdict, and how such verdict is enforced when it orders the demolition of a building constructed without lawful rights. This research employs a normative juridical method, utilizing a statutory, conceptual, and case approach. The data were collected through literature studies, including laws and regulations, court decisions, and scholarly legal writings, and were analyzed qualitatively. The findings indicate that the High Court correctly applied core legal principles in adjudicating the case, particularly the principles of legal certainty and corrective justice. The decision ordering the demolition of a permanent structure was found to be legally valid and binding, as it had acquired permanent legal force (inkracht van gewijsde). The enforcement of such a decision falls under the category of real execution as regulated in Article 200 of the HIR (Herzien Indonesisch Reglement) and Article 218 of the RBg (Reglement op de Burgerlijke Rechtsvordering). Nonetheless, its implementation often faces technical and non-technical obstacles, including resistance from the losing party and administrative delays, which necessitate effective coordination with court officers and enforcement agencies. This study concludes that clear and enforceable court rulings are essential in resolving land and property disputes, and that strengthening institutional capacity in the execution of court judgments is crucial to realizing substantive justice in civil law enforcement.