Open Parking Garage, Natural Ventilation, IBC 2018

[redbird11]

406.5.2 Openings. For natural ventilation purposes, the exterior side of the structure shall have uniformly distributed openings on two or more sides. The area of such openings in exterior walls on a tier shall be not less than 20 percent of the total perimeter wall area of each tier. The aggregate length of the openings considered to be providing natural ventilation shall be not less than 40 percent of the perimeter of the tier. Interior walls shall be not less than 20 percent open with uniformly distributed openings.

Question - If a rated wall is required between garages because allowable area is being exceeded, both are S-2, and fire shutters are used to allow the drive aisles to continue from one to the other, can that wall be included in the ventilation calculation?

 

[RLGA]

To answer your direct question, I would say no, since the doors would not be open during a fire event, which means the openings would be providing the required ventilation when they are most needed.

With that said, why is the fire wall needed? (You mention allowable area, but is a fire wall your only option?) Is this a stand-alone garage or a garage integrated with other occupancy groups? What is the construction type?