What criterion is used to determine the number of watchpersons needed on large construction sites?

The criterion for determining the number of watchpersons needed on large construction sites primarily focuses on the size of the building. Larger buildings typically present more complex safety and security challenges due to their size, height, and the ongoing activities involved in construction. A larger site may require more vigilant supervision to ensure compliance with safety regulations, monitor the activities of many workers, and manage the potentially increased risks associated with larger operations.

Factors such as the number of workers or the specific materials used may also play a role in safety planning, but they are secondary to the fundamental risks and requirements that arise from the sheer scale of the construction project. In addition, the duration of the construction project does not directly correlate with the need for watchpersons, since even short-term projects can require significant oversight depending on the building's specifications.