Today, the demand for higher building security has grown considerably, especially for evacuations in cases of fire, chemical, biological and radiological incidents or terrorist attacks. However, the planning of relevant safety measures for new buildings or the evaluation of existing buildings requires reliable information for a farsighted decision making. Simulation tools that can realistically map the spread of fire, smoke and pollutants in buildings already exist, but they are conventionally based on 1D or single zone static models which allows only rough estimation of the safety. As a result, decision making is typically very conservative and does not consider the consequences of possible intervening measures. Accordingly, safety and rescue operation plans are subject to a high degree of uncertainty with regard to their effects. Therefore, more and more often realistic 3D CFD simulations are being asked for, which is becoming possible with the continuous growth of computer power. However, such simulations are still very costly and time-consuming, especially with regard to the involved modelling efforts.