Smart Adaptive Reuse of Vacant Assets for Aging Societies: Integrating IoT-Based Care Systems with Spatial Reconfiguration

South Korea faces a “twin crisis” of a super-aged society and urban vacancies, yet traditional adaptive reuse focusing on physical renovation fails to address the critical caregiver shortage. To resolve this, the study proposes a “Smart Adaptive Reuse Model” that fuses spatial reconfiguration with IoT-based care technologies. A comparative analysis of Japanese cases was conducted using two datasets: the “physical-centric phase” (dataset A, pre-2015), focused on hardware improvements, and the “tech-enabled phases” (dataset B, 2020–2024), which utilized digital transformation strategies. Results indicate that while early models struggled with the surveillance of blind spots in complex layouts, recent tech-integrated models successfully mitigated these issues and improved workforce efficiency through “data-driven layouts” without major structural changes. Consequently, this research suggests a “Hybrid Retrofit” framework strategy for Korea—minimizing physical intervention while maximizing digital monitoring—and recommends a regulatory sandbox for “Smart Care Infrastructure” to ensure operational sustainability.