This article describes how to heat the building through the basement in the winter season. The factors which influence the basement heat loss and the design requirements for protective structures of basements are provided. Two methods of calculating heat losses of unheated basement rooms are presented. The first method of calculation assumes that all surfaces in contact with the soil array are divided into zones with coefficients taking into account the effect on the heat loss through the ground for the entire period of heating. The second method calculates the monthly heat loss from the building through the surface in contact with the ground. According to these methods, calculations and comparative analysis of methods for calculating the heat of basements are provided, as well as pros and cons of the above techniques are established. The analysis of the boundary conditions of numerical simulation of temperature fields of the soil mass is held. While building a two-dimensional temperature field to determine the linear heat transfer coefficient significant differences in the simulation results are found, which depends on the boundary conditions of the array of soil at depth. The work sets geometric parameters of the simulation of temperature fields and heat flux for the node with a soil file, but without providing data on the quantitative characteristics of the heat flux on the vertical of the soil mass.