Most of Italian historical centers are characterized by the presence of interconnected unreinforced masonry (URM) structures, commonly referred as aggregate buildings, which have shown significant seismic vulnerability over time. These structures are generally composed of units with varying geometries and materials, which have been subjected to structural changes over the course of their lifespan. The uncertain degree of connection between the units makes modeling their seismic response challenging in the absence of specific guidelines. Traditional seismic modeling of URM aggregates often oversimplifies the matter by considering units as either separated or rigidly connected, which does not accurately reflect the real complexity of their dynamic behavior.