In buildings classified in occupancy group E and 100 feet or more in height, how many elevators must be available for fire department use?

In buildings classified in occupancy group E and reaching a height of 100 feet or more, the requirement for fire department-use elevators is strictly defined to ensure effective evacuation and accessibility during emergencies. The correct choice emphasizes the need for every elevator car to be available for use when a floor is serviced by three or fewer elevator cars.

This requirement is critical because, in such high-rise buildings, where potential emergencies like fires can occur, the reliability and availability of elevators for emergency personnel are paramount. If a building only has three or fewer elevators servicing a floor, it is essential that each one is in working condition and accessible, as this provides the fire department with the necessary mobility to effectively respond to incidents.

In contexts where buildings have more than three elevators servicing a floor, different regulations come into play, as the distribution of elevators gives way for redundancy and alternative access routes for fire department operations. Thus, the focus on ensuring every elevator car is available in these scenarios underlines the priority of safety and efficient emergency response in high-rise buildings.