What is the minimum required opening-to-wall area ratio for an open parking garage on each tier?

The minimum required opening-to-wall area ratio for an open parking garage on each tier is indeed defined as a minimum required ratio. This is crucial for ensuring adequate natural ventilation, which helps to mitigate the buildup of hazardous fumes and maintain a safe environment for both vehicles and individuals. By establishing a minimum requirement, building codes are designed to promote safety standards in these structures, ensuring that they remain effective in supporting airflow while also addressing other factors such as light penetration and visibility.

A specific fixed ratio would not be appropriate as parking structures may vary in design and location. Thus, flexibility in determining the ratio allows designers to adapt to different site conditions and comply with local regulations. The concept of having no requirements or suggesting an optional ratio would not provide the necessary safety measures that minimum standards are intended to ensure.