A building management system that determines space utilization in a building. The building management system comprises room utilization sensors, such as occupancy sensors, a gateway that gathers raw occupancy data records from the occupancy sensors, and at least one processor. Each raw occupancy data record comprises an occupancy state associated with a timestamp. The processor is configured for normalizing the raw occupancy data records into normalized occupancy data records each comprising a time segment and an occupancy state indicating whether for a given time segment a room is occupied. The processor is further configured for structuring the normalized occupancy data records by associating each normalized occupancy data record with a space node corresponding to a room in the building from where the raw occupancy data record was collected and associating each space node with a set of tags, each tag defining a single state from a plurality of states. The processor may further receive a selection of a tag from a user interface, split the normalized occupancy data records along the selected tag's states into sets of normalized occupancy data records, for each split set of occupancy data records, calculate at least one occupancy rate, and display a visualization of space utilization of the building comprising a comparison of the occupancy rates of the selected tag's states.