In this paper is shown the possibility to modernize fire protection engineering in a way that it will be on the same level as other parts of the design of a building. A fire simulation model will be presented shortly. The model predicts the time for smokelogging, flash-over and detection events for a given geometry of the building. The input parameter is the fire growth curve. In a special section it is shown how the fire growth can be predicted. Sometimes the fire area is known, but more often statistical information has to be used. Finally some engineering applications are indicated, where the consequences of a fire in a bus garage and a textile factory are discussed.