Works carried out as part of the scientific project titled “Unwanted space. Cross-border and intercultural conditions for architectural protection of the heritage of modern times – part II”, were the completion and complement of research on the contemporary issue of protection of contemporary cultural heritage. The work presents original studies and reflec-tions on selected issues concerning the context of modernization phenomena, so important for the development of architecture and construction in the period of the Polish People’s Republic. The aim of the work was to find contexts and starting materials of Polish mod-ernization in 1945-1989, which will become the starting point for the future assessment of the most interesting and the most valuable achievements of post-war Polish architecture and urbanism. The contents contained in it are the result of systematic research carried out for over a dozen years by the author over architecture and urban planning in Poland during the communist period. The collected iconographic material was collected from available literature, as well as from Polish and German archives.