The problem of efficient use of energy and the problem of energy conservation inside a building when comfort conditions are given are complex problems that attracted the interest of scientific researchers in the last decades. This paper presents the ways of solving the problem of efficient utilization of energy in buildings. In the beginning is defined the problem of optimizing energy consumption in buildings, the subjects of interest being: power, comfort and control. Next we briefly introduce conventional control systems in buildings and describe their advantages and disadvantages. The focus is on techniques of artificial intelligence (AI) that have been applied for the control of both conventional buildings and those bioclimatic. We describe how the development of intelligent control systems improve the efficiency of control systems for environmental management inside the building, taking into account user preferences. Control systems that incorporate autonomous software agents, known as control agents, provide a base for the autonomous control of distributed systems sensor/actuator. By sharing information and in special cases reasoning, control agents may use in conjunction resources of the control system in a manner that view system tasks at a global level. In the following we describe an application for the control of heating systems in buildings, with particular emphasis on heating, ventilation, air conditioning and domestic hot water production. The application uses a multi-agent control.