A method and/or system for assessing the security situation in a building through an evaluation of sensor values provided by activity sensors situated in the building, in particular, in the accommodation region, an estimate of the number of persons actually present in the building, determining the number of persons to be expected in the building by an evaluation of administrative data (HR, Outlook, events, occupancies, etc.). Based upon a comparison of the number of persons to be expected with the number of actual persons, an indicator is determined for assessing the actual security situation in the building or in the accommodation region.