Aggregate buildings are an essential component of Italy's cultural heritage, but their seismic response is a crucial factor in determining their safety and structural integrity during earthquakes. These buildings are frequently a part of a whole structure composed of interconnected or related units, which could differ in geometry, construction systems, and materials. Accurately modelling these buildings is still a challenge due to their complex structural behavior, local failure mechanisms, and uncertainties regarding the degree of connection between units. The lack of standardized and consistent procedures has also resulted in multiple modeling approaches that tend to over-simplify the structure. During the seismic response assessment of a unit, it is fundamental to consider the influence of the interactions with adjacent structures because of their different response.