Since the second half of the XX century, the way new urban areas have risen next to the ancient/traditional parts of cities has been vastly unsystematic, often altering the original natural landscape and/or urban morphology significantly. This has sometimes generated a mixture of architectural languages and technologies without any regard for the connectivity of a community as a whole. Despite the revival in current design practice of passive design solutions, studies on the influence of contemporary urban settlements on the thermal behavior of traditional buildings are still very limited. The aim of this study is to investigate, through simulation-based assessments, how contemporary urban settlements and buildings affect the bioclimatic features of existing historic architecture. The analysis considers some case studies located in different countries and climates and moves from a micro-urban to a building scale.