This research examines the emerging Blended-Use concept, an evolution of traditional Mixed-Use development, and explores its design implications. It then applies its design principles to Palazzo Raspanti, a 16th-century building in the center of Treviso, a medium-sized Italian city. Unlike mixed-use development, which typically has a more static quality, blended-use recognizes the temporal aspect and the dynamic, evolving functions that can exist within the same space over a short period. The goal of this research is to expand the architectural understanding of blended-use by adopting a more comprehensive perspective that includes both spatial and temporal theories, as well as integrating circularity and sustainability concepts. After reviewing existing literature, case studies, and conducting expert interviews, this study aims to clarify the relationships among the concepts of fourth place, hybrid-use, blurred-use, and blended-use at the building scale in the short term, proposing a new framework to define these ambiguous terms. Consequently, it introduces a new term: the Synergy Hub, a concept to describe blended venues that combine living, working, and leisure activities in a circular and holistically sustainable manner. Using insights from the initial research phase, a design phase will visualize potential future functionalities and pedestrian flow within Palazzo Raspanti. The thesis will focus specifically on the future design of its ground floor, garden, and surrounding areas. The study will conclude by suggesting directions for future research to improve multiple aspects related to blended-use, especially in connection with the case of Palazzo Raspanti.