The purpose of the study is to emphasize the importance of including in the register of cultural monuments and being part of the State Architectural and Historical Reserve “The Museum of St. Sophia Cathedral” (now – The National Sanctuary Complex “Sophia of Kyiv” architectural monuments of the 19th century, a former deacon’s wing, in order to preserve the integrity of the architectural ensemble of the Kyiv-Sophia Cathedral, as well as to emphasize the connection of the Strilets-Morozovs family with social, religious and cultural processes that took place in the 20s – the 30s of the twentieth century on the territory of Ukraine. The research methodology is based on general scientific and special methods, in particular, the historical method is used. Methods of bibliographic, archival, iconographic research, as well as empirical methods such as observation, field study and comparison are applied. The scientific novelty of the study is that for the first time in the context of the architectural monument’s history of the late 19th century, the former cathedral (deacon’s) wing, one of the aspects of the Hryhorii Kosynka’s memorization was considered, while the memorial plaque to the writer of the Ukrainian shot revival acts as one of the images of historical memory, and is also an element of the cultural heritage object. Conclusions. The installation of the memorial plaque for Hryhorii Kosynka meant the appearance of a new “place of memory”. It became an integral part of the history of the former cathedral (deacon’s) wing. Its inclusion in the architectural and historical reserve favourably affected the preservation of the architectural monument of the late 19th century and the integrity of the architectural ensemble of one of the largest museum complexes in Ukraine.