Supply–Demand Adaptability Assessment and Optimization Strategies of Community Service Facilities Based on Built Environment Typology: Evidence from 15-Minute Life Circles in Xi’an, China

Clarifying the mechanism through which community-built environment types influence the supply–demand adaptability of service facilities can promote the effectiveness of community service facility provision in the context of urban renewal. Existing studies have focused on facility quantity, service radius, or accessibility, while few have integrated community-built environment classification with supply–demand adaptability assessment. As a result, the differentiated mechanisms of facility mismatch under different spatial structures remain insufficiently revealed. Taking Xi’an as an example, this research takes 15-minute life circles as basic units and integrates macro- and micro-scale built environment indicators to identify community types. Then, it assesses the supply–demand adaptability of service facilities from four dimensions, including completeness, accessibility, diversity, and equity. The results show that supply–demand adaptability of community facilities is jointly influenced by factors such as road networks, residential complex scale, and walking environment quality. Facility provision adaptability in Xi’an generally shows a declining spatial pattern from the urban core to peripheral areas, while different indicators reveal different types of mismatches. Facility layout patterns act as an intermediate spatial mechanism linking community morphology with supply–demand adaptability outcomes. Their service performance is conditioned by road network permeability, block size, and residential enclosure. Based on these findings, this study proposes targeted optimization strategies for different community types, providing a reference for diagnosing supply–demand conflicts within 15-minute life circles.