The aim of the research is to find the conditions for achieving minimum of energy loss when heating a building in central heating system. Relevance of research. Rapidly growing world energy consumption has already raised concerns over supply difficulties, exhaustion of energy resources and heavy environmental impacts (ozone layer depletion, global warming, climate change, etc.). The solution of the arising problems requires exact physical and mathematical modeling of energy transport and consumption. The analysis of this model using the methods of optimization theory will allow finding the best solutions of energy supply. Research methods: analysis and generalization of previously obtained theoretical results and formulation of new approaches. Results. The paper introduces a brief review of strategies and methods of effective energy supply for public, commercial and residential buildings use. The increasing attention is paid to the central heating system. Providing power effective heat supply is considered as a mathematical minimax problem. The authors have stated the problem of optimizing heat supply of the building connected to the central heating system. The criterion of optimality is maintenance of temperature comfortable for a person in the building and minimum of energy losses. The simplest private solutions of a task are found and necessary settlement formulas for providing an optimality of heat supply are offered. A new equation for the ideal temperature chart - the dependence of the coolant temperature on the outdoor temperature - is obtained. There are two most important parameters: 1) the rate of heat transfer between the heaters and the rooms of the building; 2) the rate of heat exchange between the building and the outside air. In the dependent heating system (without technology of underground energy storage) the best solution are the following: 1) the decrease of the effective coefficient of heat transfer through external walls; 2) strict respect to the temperature chart, and it must be individualized for each building.