This study examines the detection of extended presence in buildings. The term refers to the recording of presence (presence yes / no), number, position, activity and identity of persons. First, the necessary basics have been compiled. This has shown that extended presence detection has not yet been taken into account by building standards. However, there are already applications for this. Then the main requirements for extended presence detectors have been defined. These must not differ significantly from conventional presence detectors (e.g. PIR) in terms of price, appearance and handling. Furthermore, four methods for recording the extended presence have been tested in real-life environments. Video-based presence detection is already available on the marketplace and allows for measurement accuracies of about ±2 persons. In the end, the benefit of extended presence detection has been determined. A significant potential for energy savings was found in functional buildings. On the other hand, conventional presence detection is to be favoured in residential buildings. Based on these results, a number of recommendations were derived for manufacturers and planners.