A Multi-Level Analytical Framework for Street Spatial Elements and Its Vitality Mechanisms: A Case Study of Seats on Pingdeng Street, Zhengzhou

Street seating serves as a critical medium for stimulating spatial vitality and holds substantial design value in the refined planning of commercial upgrading and quality enhancement in aging districts. As urban regeneration and the optimization of existing built environments have become dominant paradigms in global urban development, the improvement of street quality—given its role as the primary setting for everyday public life—has increasingly depended on the fine-grained design and precise regulation of micro-scale environmental elements. This study takes Pingdeng Street in Zhengzhou, China, and its 33 seating installations as an empirical case. A multi-level analytical framework—comprising the seating ontology level, the seating space level, and the street environment level—was developed to quantitatively examine the relationships between multi-level spatial elements and street vitality intensity. Through correlation and regression analyses, the study systematically investigated the mechanisms by which seating-related elements at different levels influence street vitality. The results indicate that the Green View Index (GVI) is the core driver of street vitality, with the most significant enhancement observed when GVI ranges between 28% and 35%. The synergistic coupling of multi-level seating elements is essential for maximizing street vitality, while optimization pathways vary across different functional seating types. In design practice, high-comfort seating with backrests is recommended, with seating continuity controlled within 0.63–0.90. Seating spaces should adopt moderately enclosed spatial forms, such as eave-covered areas, and be supplemented with adequate lighting facilities. At the street environment level, a GVI of 28–35% and spatial openness of 9–18% should be maintained. The multi-level analytical framework and quantified indicator thresholds established in this study offer a new perspective on the mechanisms linking seating and street vitality. The findings provide a scientific theoretical basis and offer context-sensitive design guidance for the refined renewal of aging urban districts under comparable conditions.