Where openings below grade are provided for required natural ventilation in motor-vehicle-related occupancies, how many times the depth of the opening must the outside horizontal clear space be?

In motor-vehicle-related occupancies, when there are openings below grade for required natural ventilation, the pertinent requirement is that the outside horizontal clear space must be at least 1-1/2 times the depth of the opening. This guideline is crucial for ensuring that air can freely circulate and maintain appropriate ventilation within the space.

The reasoning behind this specification is based on safety and efficiency in ventilation design. A clear space beyond the openings allows for unobstructed airflow, which is essential in environments where motor vehicles are present. Proper ventilation helps mitigate the accumulation of harmful gases and ensures a healthier atmosphere.

This guideline helps create a balance between the structural elements of the building and the functional requirements for ventilation. Following these specifications supports both compliance with building codes and the overall safety of the facility.