What type of fire escape is acceptable in most commercial buildings?

Stairways that lead directly to the outside are an acceptable form of fire escape in most commercial buildings due to their effectiveness and reliability in providing a safe egress route during an emergency. These stairways are typically designed to be wide enough to accommodate the rapid movement of occupants during a fire or other emergencies. They also offer a protected means of egress that can be accessed easily, minimizing the risk of smoke inhalation or injury.

In comparison, other options, such as rope ladders, fire escape slides, and windows that can be opened, are generally not considered practical or safe for use in commercial settings. Rope ladders can be difficult to deploy quickly and may not support the weight of multiple evacuees. Fire escape slides also present limitations in terms of safety and ease of use. Openable windows might not provide a reliable or sufficient exit, especially in high-rise buildings, where occupants may be unable to reach the windows or where the openings can be obstructed. Therefore, stairways designed for emergency egress are the standard and preferred method of fire escape in commercial buildings.