At the preliminary design stage of the pit excavation, it is necessary to perform calculations of various options for assessing the impact of the process of the excavation on the surrounding building. Currently, the analysis of changes in the stress – strain state of the soil mass during the construction of pits is carried out using numerical methods, the most widespread of which is the finite element method, implemented in a variety of calculation complexes. It is obvious that at the current level of development of computer technology, this method allows us to take completely into account all the factors that affect the final result. At the same time, even solving the problem in a two-dimensional formulation takes a lot of time and requires the necessary qualifications of the personnel performing the calculations. Taking this into account, it remains relevant to develop new engineering methods that allow performing the required calculations quickly and with sufficient accuracy at the stage of preliminary variant design. The article considers a numerical-analytical method for the operational assessment of the impact of the pit excavation on the deformation of the adjacent soil mass, taking into account the stiffness of the enclosing structure. The method is based on solving the Melan problem and numerical modeling using the experiment planning method. The stress-strain state of the soil mass, determined analytically, is corrected by selecting the stiffness of the structure enclosed of the slopes of the excavation. The results of the analytical solution were compared with the results of calculations performed using FEM, and showed convergence in the range of 5-20%, which is in good agreement with the accepted engineering accuracy of calculations. The method, as an alternative, can be used at the preliminary stage of designing of pits excavation.