Abstract Objectives: This study aimed to investigate vertical care models for older adults in high-density urban environments through a comparative case analysis of U City , Kampung Admiralty , and The Clare . The objective was to establish a robust foundation for designing vertically integrated housing for older adults to accommodate the growing ageing population in densely populated cities. Methods: An interdisciplinary approach integrating literature analysis, conceptual modeling, and comparative case studies was adopted. Building on cross-disciplinary interpretations of the micro social unit, a theoretical framework was developed to examine vertically integrated housing for older adults in high-density urban environments. This framework comprises three analytical dimensions: social openness, which emphasizes social connectivity and urban permeability; temporal adaptability, which ensures responsive services aligned with the evolving needs of aging individuals; and functional integration, which examines internal coordination and synergistic interactions within multi-functional spatial systems. Representative cases were selected via theoretical sampling to ensure contextual diversity and data reliability. Each project was evaluated using three indicators—social openness, diversity of care types, and degree of functional integration—to assess the capacity of vertical housing complexes to integrate living, care, and social participation within a unified urban framework. This multi-layered methodological approach enabled both analytical depth and cross-contextual comparison, thereby revealing the adaptive potential of the micro social unit paradigm. Results: A comparative analysis has been conducted on three different housing models for older adults, all of which are vertically integrated. This analysis illustrates several core design principles. Functional integration in the vertical dimension is achieved through the stratified organization of diverse living arrangements, enabling residential, medical, educational, and commercial functions to coexist and interact within a shared physical structure, thereby forming an integrated whole. Public interface design emphasizes cross-generational and cross-group interaction through open ground floors, semi-open walkways, and shared rooftop spaces. The vertical housing model represents not only an innovation in spatial configuration but also a strategy for social integration, reconfiguring older adults’ sense of belonging in high-density urban environments through deliberate spatial organization and transforming architecture into a multidimensional medium for social diversity and humanistic care. Finally, the integration of diverse care models for older adults within a single building ensures adaptability to the evolving needs of aging populations. Conclusions: This study highlights the ageing population and the effective design of vertically integrated building types, particularly in high-density cities. The findings demonstrate that the micro social unit framework offers an effective strategy for addressing the challenges of the ageing population within high-density urban contexts. Based on this framework, vertically integrated elderly housing can redefine ageing as a spatial condition of connection, functioning as an active platform for continuous personal growth, social reintegration, and urban renewal.
Shi et al. (Mon,) studied this question.