What is the maximum number of seats with backrests allowed per row in a smoke-protected aisle with a 12" clear width aisle accessway?

In a smoke-protected aisle, the maximum number of seats with backrests allowed per row is determined by the width of the aisle accessway and the need for clear egress during emergencies. With a 12-inch wide clear accessway, this width is significant as it must accommodate the flow of individuals during evacuation.

Typically, the National Fire Protection Association (NFPA) standards and other building codes will specify the maximum number of seats based on the clear width of the aisle. In this case, the standard permits a specific ratio of seats to the width of the aisle, primarily to ensure sufficient space for safe and unimpeded movement.

For a 12-inch wide clear aisle, allowing seven seats with backrests per row aligns with safety regulations, ensuring that there is an adequate escape route should an emergency arise. This configuration offers an optimal balance between seating capacity and the accessibility required for safe evacuation, which is a priority in smoke-protected areas to minimize the risk of injury or entrapment.

In summary, the allowance of seven seats per row in a smoke-protected aisle supports safety standards aimed at ensuring that there is sufficient egress space available while still optimizing the area for occupancy.