<![CDATA[This study aims to analyze the legal framework governing apartment ownership in Indonesia and Singapore and to compare the degree of legal certainty provided by both systems in protecting owners’ rights. Legal certainty of apartment ownership in Indonesia still faces several issues, including the dependence of Ownership Rights to Apartment Units (HMSRS) on land rights, a non-integrated registration system, and the evidentiary weakness of Apartment Ownership Certificates (SHMSRS) which remain challengeable. This research is important due to the limited comparative studies examining legal certainty of apartment ownership through indicators of ownership structure, registration systems, relationship with land rights, and evidentiary strength of ownership certificates. This research employs normative legal methods through statutory, conceptual, and comparative approaches. The findings reveal that Indonesia still experiences regulatory fragmentation, dependence of HMSRS on land rights status, and a non-integrated registration system, while Singapore applies a centralized electronic registration system based on the principle of indefeasibility of title which provides stronger legal certainty. The study concludes that the integration of legal and registration systems constitutes the primary factor in determining legal certainty of apartment ownership. The novelty of this research lies in its comparative analysis that positions ownership structure, registration systems, relationship with land rights, and evidentiary strength of ownership certificates as the principal indicators of legal certainty in apartment ownership. Penelitian ini bertujuan menganalisis pengaturan hukum kepemilikan rumah susun di Indonesia dan Singapura serta membandingkan tingkat kepastian hukumnya dalam menjamin perlindungan hak pemilik. Kepastian hukum kepemilikan rumah susun di Indonesia masih menghadapi berbagai persoalan, seperti ketergantungan Hak Milik atas Satuan Rumah Susun (HMSRS) terhadap hak atas tanah, sistem registrasi yang belum terintegrasi, dan kekuatan pembuktian Sertifikat Hak Milik atas Satuan Rumah Susun (SHMSRS) yang masih dapat digugat. Penelitian ini penting dilakukan karena kajian komparatif mengenai kepastian hukum kepemilikan rumah susun melalui indikator struktur hak, sistem registrasi, hubungan dengan hak atas tanah, dan kekuatan bukti kepemilikan masih terbatas. Penelitian menggunakan metode hukum normatif dengan pendekatan perundang-undangan, konseptual, dan perbandingan. Hasil penelitian menunjukkan bahwa Indonesia masih menghadapi fragmentasi regulasi, ketergantungan HMSRS terhadap status hak atas tanah, dan sistem registrasi yang belum terintegrasi, sedangkan Singapura menerapkan registrasi elektronik terpusat dengan prinsip indefeasibility of title yang memberikan kepastian hukum lebih kuat. Penelitian ini menyimpulkan bahwa integrasi sistem hukum dan registrasi menjadi faktor utama dalam membangun kepastian hukum kepemilikan rumah susun. Kebaruan penelitian terletak pada analisis komparatif yang menempatkan struktur hak, sistem registrasi, hubungan hak atas tanah, dan kekuatan bukti kepemilikan sebagai indikator utama kepastian hukum rumah susun.]]>
