Universal Design-Based Integration of UDET, Spatial Syntax and QCA Methods for Equitable Child-Friendly Environment Planning A Multilevel Decision Framework

Child-friendly environments are increasingly promoted in urban planning, yet many such spaces remain shaped by adult-centered norms and standardized safety principles, limiting their ability to accommodate children’s diverse physical, sensory, and developmental needs. Although Universal Design (UD) offers an inclusive theoretical foundation, its practical application in child-oriented environments has often lacked empirical grounding and decision-oriented evaluation tools. This study explores how UD principles can be operationalized in child-friendly environments through a multilevel, mixed-method framework. Three public children’s spaces in Beijing, Shanghai, and Guangzhou were examined using sequential quantitative and qualitative approaches. Quantitative analyses combined Universal Design Evaluation Tools (UDET), spatial syntax indicators, and multilevel linear models to examine relationships between spatial characteristics and children’s behavior. Qualitative insights were derived from participatory observation, child-led visual methods, and stakeholder interviews, and were integrated using an explanatory spiral approach. Qualitative Comparative Analysis (QCA) was further applied to identify combinations of design conditions associated with inclusive outcomes. The findings indicate that physical accessibility, sensory inclusivity, and risk gradation influence children’s engagement in distinct but interrelated ways. Spaces that simultaneously supported accessibility and sensory regulation showed substantially higher participation, particularly among children with disabilities and neurodiversity. Spatial configuration also played an important role, with integration, intelligibility, and visual connectivity shaping patterns of engagement and exploration. Rather than relying on single design elements, inclusive child-friendly environments emerged from specific combinations of spatial, sensory, and social conditions. Based on these results, the study proposes a Child–Environment Fit Index (CEFI) to support evidence-informed planning and design decisions. The framework contributes to a more grounded understanding of how universal design principles can be translated into inclusive, context-sensitive child-friendly environments.