What percentage of the wall length can the aggregate width of openings at any floor level not exceed?

The correct answer indicates that the aggregate width of openings at any floor level should not exceed 25% of the wall length. This restriction is in place to ensure the structural integrity of the building. Openings such as windows and doors can significantly affect the load-bearing capacity of walls. By limiting the total width of these openings, the design maintains adequate wall strength and stability. This is particularly important in commercial buildings where safety and structural performance are critical.

Choosing a percentage that is too high would compromise the wall's ability to support loads and provide resistance against lateral forces, such as wind or seismic activity. The limit of 25% strikes a balance between allowing natural light and ventilation while ensuring the essential structural functions of the walls are preserved.