What occupancy is this? Generator Room at parking garage

[Yikes]

Existing hotel has a 178kw Cummins diesel generator in its own sprinklered 11'x20' room that was constructed
as part of an on-grade S-2 sprinklered parking garage.
Generator air supply and exhaust is vented to the exterior and is completely separated from the garage by
8" concrete walls, floor and ceiling. Generator sits on a sub-base storage tank ("skid mount") that holds about
380 gallons of diesel fuel.

What kind of occupancy is this?

1. H-2 occupancy because it is "combustible liquid" per CBC Table 307.1(1) ? Or, per footnote e of Table 307.1(1), is a skid-mount storage tank allowed a 100% increase in storage quantity, such that when added to the 100% increase for a sprinklered building, the tank too small to qualify as an H-2 occupancy? Is the presence of a skid tank for a generator even considered as "fuel storage" (see footnote p.2 of Table 307.1(1),
2. If not an H-2, then is it an S-2 occupancy (CBC 509) because it's an incidental use less than 10% of the area of the S-2 garage?
3. Or is it a U occupancy (CBC 312) if it doesn't neatly fit any other description?

 

[Yikes]

Bump.

Any takers?

 

[TheCommish]

What is the generator supplying? If it is the building that it is in, I would consider it part of the garage. having a concrete wall does not make it a separate building or use

 

[Mr. Inspector]

#2

 

[Yikes]

The Commish and Rick18071, it is part of the garage, so I think you are helping me to confirm it is an S-2 incidental use.