Building energy performance simulations are commonly used in designing and managing buildings. Occupancy levels play a big role in a building's energy use. Researchers studied how different levels of detail in occupancy data affect the accuracy of these simulations. They looked at data from a large educational building, comparing whole-building occupancy with detailed zone-level occupancy. The results showed that while higher resolution occupancy data didn't necessarily improve overall energy accuracy, it did improve accuracy in areas related to occupancy, like ventilation energy use.