Impact of Built Environment Subjective Evaluation and Utilization on Older Adults’ Mental Health: A Case Study of Guangzhou

China is currently experiencing an aging population. Moreover, the overall health status of older adults in China remains a concern, with mental health issues becoming increasingly prominent. Early research on older adults’ mental health focused mainly on environmental determinants, particularly the objective characteristics of the built environment. Recently, the impact of the Built Environment Subjective Evaluation (BESE) on mental health has gradually attracted scholarly attention. Most studies have neglected the influence of Built Environment Utilization (BEU) or actual activities occurring in these spaces on mental health outcomes. To address this gap, this study uses data from older adults in 20 communities in Guangzhou, China, and applies structural equation modeling to examine the relationships between BESE, BEU, and mental health among urban older adults, with a specific focus on the mediating roles of social capital, place attachment, and community participation. The results indicate that (1) older adults’ BESE levels show a significant positive correlation with their mental health status, with those with a more positive BEP exhibiting a tendency for better mental health. BEU also demonstrated a significant positive association with mental health among older adults. The BEP significantly affected mental health across all income levels. However, the BEU significantly affected mental health only in the low-income group. (2) Structural equation modeling results showed that both BESE and BEU have significant positive correlations with older adults’ mental health. Notably, compared with the objective features of built environments, older adults’ actual activities in community environments have a more significant impact on their mental health. This indicates that improving older adults' satisfaction with and frequency of using community environments effectively enhanced their mental health. (3) Mediation analysis revealed that place attachment is essential in mediating role between BESE and mental health. Specifically, older adults with higher BESE and BEU scores, potentially because of the intrinsic protective mechanisms of place attachment, were more likely to actively participate in community activities, thereby reporting better psychological states. We found no evidence that strengthening social capital alone can mediate the association between BESE and mental health. (4) The impact of BESE and BEU on the mental health of older adults varied according to age group, education level, and income level. These findings provide practical guidance for developing aging-friendly communities in China. This study revealed significant associations between BESEs/BEUs and older adults' mental health, with utilization behaviors showing more prominent effects. Thus, social capital, place attachment, and community participation play significant mediating roles. This study highlights the need to address internal heterogeneity among older adult populations. Particularly for low-income older adults, planners, designers, and policymakers should prioritize the provision of physical exercise facilities and ensure the safety and comfort of public open spaces.