The paper describes integrated building management system climate control principles based on event forecast with respect to minimization of energy consumption. The method uses appropriate control algorithm when environment events can be forecasted. Conference room control method is described in the example. Three different control models are compared in the paper: standard, event-based and event forecast. To compare model energy efficiency computerized models with various thermal and environmental parameters are used. System model research shows that event forecast method is the most energy efficient, but amount of energy economy is not significantly bigger comparing to other compared methods