Shape generation rules in the course of building design reflect not only on the architectural building peculiarities but also on the building energy efficiency. This is the reason why, it is necessary to start project design on architecture and space planning solutions and rational shape organization.Theoretical and practical value of work is that the calculation of optimum form generation based on variational calculus allows to choose the necessary configuration of walling construction for comfortable microclimate and heat balance inside the structure and provide the necessary rate of building energy efficiency.