How Community-Built Environment and Social Capital Are Jointly Associated with Multidimensional Health in China: A Compensatory–Synergy Perspective

Community social capital (CSC) and the community-built environment (CBE) are key resources associated with residents’ health, yet their combined associations with multidimensional health and well-being remain insufficiently understood. Drawing on large-scale data from the 2018 China Labor-force Dynamics Survey, this study analyzed a filtered sample of 14,127 respondents nested within 326 communities and employed multilevel models to examine the direct, interactive, and combined associations of CSC and CBE on four outcomes: residents’ self-rated health, subjective well-being, loneliness, and mental health. The results identified two CSC indicators: neighborhood mutual support and resident relationship quality, and two CBE indicators: community type and residential density, as key factors associated with multidimensional health, each showing significant associations with multiple health outcomes, with CSC indicators demonstrating relatively stronger and more consistent effect sizes than CBE indicators. The study further identified a dual mechanism involving key indicators of CSC (relationship quality and neighborhood mutual support) and CBE (community type and residential density). When one dimension was constrained, the other was associated with compensatory patterns in residents’ health, whereas high levels of both social and physical resources were associated with synergistic advantages. Stratified analyses revealed that individuals with low external social engagement appeared more sensitive to these environmental associations. This study emphasizes that sustainable community planning and governance should consider key social and physical indicators to support both social sustainability and built-environment sustainability. Depending on the level of community resources, it may be beneficial to leverage the compensatory and synergistic patterns among different community attributes to support improvements in residents’ health benefits. Particular attention may be warranted for individuals with low social engagement to build healthier and more sustainable communities. This research advances an integrated resource configuration framework that contributes to a shift in urban health governance from isolated environmental interventions toward an adaptive, balanced approach.