The Evolution of Plot Morphology and Design Strategies in Built Heritage Renewal in Central Shanghai from the Perspective of Sharing Cities

With the rise of the sharing economy and the concept of the sharing city, the field of urban renewal is facing new opportunities and challenges. This paper innovatively explores built heritage renewal in central Shanghai from the perspective of the sharing economy, focusing on the evolution of plot morphology and associated design strategies. Six representative cases, selected within the framework of three urban renewal policies from 1999 to the present, are analyzed using a diachronic method based on the Conzen school and the street frontage index. Combined with historical maps, aerial photographs, and satellite images, the paper analyzes the changes in plot morphology from 1999 to 2024. The paper highlights how the introduction of sharing city principles significantly impacted plot morphology, facilitating the expansion and diversification of space use and driving the restructuring of plot boundaries, including physical, property, and activity boundaries. The study further reveals how the shared city concept has led to the emergence of privately owned public spaces. Additionally, the paper discusses the pursuit of flow, openness, and sharing in urban renewal, noting how these factors have shifted the focus from purely rentable and sellable areas to more efficient space resource allocation, optimizing spatial configurations. Finally, the paper introduces the concept of “sharing by transfer”, proposing that adjustments to plot boundaries under the sharing economy framework can foster more equitable, efficient, and sustainable urban renewal, providing new perspectives and strategic recommendations for built heritage renewal.