One of the most progressive problems of modern urban planning is the gradual decrease in areas suitable for construction, especially within the historical districts of cities. This prompts developers to increasingly develop sites in difficult engineering and geological conditions, which are often located within dense buildings.
 Today, the construction of multifunctional residential complexes combines the construction of high-rise residential sections and commercial real estate buildings with multi-level parking lots, which are often located in close proximity to each other. Often, the sequence of construction of these buildings is stretched over years or even decades, for example, due to an unfavorable economic climate or the instability of the political situation in the country, which leads to the commissioning of only certain stages of construction. The subsequent resumption of construction work requires taking into account the mutual impact of new construction and observations of previously constructed buildings during the construction of new structures.
 The execution of deep pits at the stage of laying the foundations of new buildings, as well as the substantial weight of high-rise buildings, causes a change in the stress-strain state of the adjacent soil massif, so designers face the task of determining the impact of such construction on the adjacent buildings.
 This article presents the results of a study of the change in the stress-strain state of load-bearing structures and foundations an existing building, taking into account the mutual impact of an adjacent high-rise section of a residential complex.
 The calculations were performed in two independent software systems Plaxis 3D and LIRA-FEM, in the spatial formulation of tasks, for a comprehensive assessment of the SSS of the system "soil base-foundation-superstructure".
 The zone of impact of new construction on the adjacent buildings, the values and character of additional displacements of foundations of adjacent structures are determined. The regularities of changes in the calculated forces in piles are shown, which indicate a decrease in axial forces in piles up to two times at the interface with the foundations of the new building and an increase in the load on the piles of the central zone by up to 17%. The obtained results show a tendency to redistribute stresses in the foundation slab from the bearing zones to the span zones, as well as in the bearing vertical structures of the lower floor of the existing building.