In this article, a study of the effectiveness of the use of a protective screen in densely built-up conditions was carried out. Based on numerical modeling, the impact of new construction on the stress-strain state of a three-story brick building was calculated. The problem was modeled in 2D and 3D settings with the input of the system "excavation structures of the pit - soil massif - protective screen - foundations of the existing building" At a distance of 4 m from the building, a pit with a depth of 6 m was excavated, as a fence of the pit, bored piles were used. The protective screen is made of piles of a metal pipe with a diameter of 159 mm, which was filled with concrete, the pitch of the piles was 0.2 m. Two tasks were solved: the installation of a pit with a protective screen between the retaining wall and the existing building and without a protective screen. The behavior of the soil mass was modeled using the Hardening Soil Model. The calculation was carried out in stages. At the first stage, the initial natural stress-deformed state of the soil massif was created. At the next stage, the operating load was transferred to the foundation structures of the building, after which the resulting deformations were zeroed. Next, piles were installed and the pit was developed step by step (in parts with a depth of 2 m). Regulatory documents declaring the limit values of additional deformations of bases and foundations in the area of compacted buildings and their dependence on the technical condition of the building were analyzed. The main causes of the deformation of the surrounding buildings in zone of influence of the new construction and measures to minimize the negative impact on the existing buildings have been established. It was found that the technology of piling the pit has a significant effect on the stress-strain state of the surrounding buildings. At the stage of drilling pile wells, additional subsidence of the foundations of the house is observed. The positive role of the protective screen in increasing the strength of the pit fence piles was also revealed. It was established that the protective screen allows to avoid an increase in the stresses of the foundations of the existing building and to limit the zone of deformation that occurs as a result of construction works.