Verify open vs. enclosed parking garage ventilation classification against IBC Section 406.5/406.6 during a fire/life-safety compliance review

Steps

1. Determine whether the structure qualifies as an 'open parking garage' under IBC 406.5 by checking that exterior wall openings on two or more sides total not less than 20 percent of the total perimeter wall area of each tier, with interior walls also required to be not less than 20 percent open with uniformly distributed openings.
2. Confirm the aggregate length of qualifying openings meets not less than 40 percent of the tier's perimeter, noting the exception allowing openings concentrated on two opposing sides instead of distributed around the full perimeter.
3. For any below-grade tier relying on openings for natural ventilation, verify the outside horizontal clear space in front of each opening meets the code's depth-based clearance requirement.
4. If the structure does not meet the open-garage ventilation thresholds, classify it as an enclosed parking garage under IBC 406.6 and confirm mechanical ventilation, more restrictive construction type, and (where applicable) automatic sprinkler requirements are met instead.
5. Confirm the jurisdiction's currently adopted IBC edition and any local amendments before citing specific section numbers and percentages, since numbering and thresholds have shifted across code cycles.