摘要：The research presents an improved method of rational design of energy-efficient low-rise residential buildings according to their life cycle. The mathematical model for finding the optimal version of draft power-efficient residential building has been developed. For conditions of Ukraine the optimization problem has been set and solved （finding the optimal version of the draft energy-efficient buildings）. The calculations prove the fact that the construction of passive houses in Ukraine today is economically feasible. Scientific and practical regulations, outlined in the research, can be used by all participants of the investment programs, and energy-efficiency projects, renovation projects and developing normative-technical documents.