In the context of modern processes of globalization, the problem of preserving architectural heritage as part of national culture is actualized. At the same time, the need for the final development of historical centers, bringing them to the modern requirements of comfort, accompanied by interference in the historical context, pose the task of developing principles and approaches to combining the “old” and “new”, taking into account the categories of “integrity”, “value”, “authenticity”, “spirit places” (genius loci) of the historical environment of the city and contributing to the continuity of urban development.The purpose of the article is to highlight the current principles and approaches to architectural activity in the current urban environment, as well as to identify the prerequisites for their formation.Based on the methods of historical research of the evolution of theoretical foundations in the field of preservation and development of historical centers of cities, the development of architectural trends of the XX century and architectural and artistic analysis of modern world design practice, the following prerequisites for the formation of modern approaches to the connection of the “old” and ”new” historical environment are identified: the development of theory and practice in the field of preservation of architectural heritage (approval of the categories “monument”, “authenticity”, “value”, “spirit of the place”, “layers of time”, etc.); the development of modernist architecture (the concept of the correspondence of architecture to its time); the development of postmodern architecture (the emergence of a modern approach, appeal to the styles of the past, “stylization”); the development of digital design technologies at the turn of the XX–XXI centuries (new possibilities of shaping, de-constructivism, nonlinear parametric architecture). The following principles of formation of approaches of modern project activity in the historical urban environment are highlighted: subordination to context (environmental approach, “stylization”); subordination of “old” and “new” (conceptual approach or equality of “old” and “new”); independence (contrast of “old” and “new”).