Determining the occupancy load for an office is a safety provision required by law. Each state has its own requirement; however, these requirements are mostly based on the National Fire Protection Association's Life Safety Code. (Reference 1) The NFPA is in charge of listing the various safety codes. This includes taking preventive measures, such as having fire exits in an office or building.
Determine the proper occupant load factor by referring to Table 188.8.131.52 of the updated Life Safety Code. Since the occupant load factor is for offices, the standard factor is 100 square feet for all business use.
Estimate the net floor area by referring to the office blueprint. If these are not available, measure the area using a tape measure. Find the two widest areas of the room and multiply them; this should approximately give you the total floor area.
Calculate the occupancy load using the following formula:
Floor area ÷ Occupant Load Factor = Occupancy Load for Office
Determine the number of exits needed by determining the number of occupants in the office. The code formulates the number of exits based on the number of occupants in the office. The minimum is two exits, and this increases as the number of occupants rises.
In an office setting, the NFPA sets 7 net square feet as the room needed per person. Requirements and guidelines may vary from state to state. Check with local authorities. Exit signs must also comply with guidelines in the Life Safety Code.