Why IEQc5 Applies to Entire Building?

We've recently achieved this credit on a project in Budapest and I believe that the tenant does benefit. For our project the requirement for walk-off mats didn't apply as we're on an upper floor, however if we had a ground floor entrance (or a retail unit.) then this would certainly be useful. The challenge for us was specifying air exhaust for the printer rooms - on the whole probably a benefit to the air quality on the floor.
The requirement to change the air filters after construction was problematic as we have 100% fresh air and this was really only an extra cost with absolutely no benefit.

Andrew and Michael
Does this credit really apply to the whole building or just the tenant part of the building?
The book says: “… at all high-volume exterior entryways”, not specifying if it’s the building as a whole or the CI project scope. The LEED Online form says: “… at all regular building entry points in the project scope”. I have a project with three exterior entries, these will have the mats. But the building can be accessed via the garage as well. However the garage is some two floors below the project scope. So it’s an interior to interior entry into the project scope. There is no room for mats here and I wouldn’t consider them an exterior entry point. We are also certifying the same (whole) building under CS. Here the garage is included in the scope of LEED and here it is clear that we would have to have mats in the elevator area from the garage. However since there is not enough space in all elevator areas we will not go for this credit here. What do you think of my CI project, go for the credit and not have mats outside the project scope in the elevator area from the garage?
Thanks!

I think that you are making Andrew's point here. Assuming that this garage serves the building occupants, the entry from the garage to the building is a regularly used entry. Per the credit, all regular entries must be addressed and protected with mats or recessed grills. However, most CI project scopes are far outside these types of entry.

Addressing your particular question, I would say that if the CS buidling does not meet IEQc5 then the tenants would never be able to meet this credit as long as they are using or have the ability to use the parking garage. If you had a ground floor tenant who did not allow their employees to use the parking garage and who installed walk off mats at the exterior door entry, then you could earn the point. This is just my opinion. Others may have project reviews that contradict this.

The garage access point is beyond the LEED project boundary and thus do not apply to this CI project. The INTENT of this part of the credit is to prevent dust particles within the CI project space. By the time they get through the lifts and into the space all the dirt is somewhere else in the building and thus no longer relevant to the CI project. Our project only had interior entrances to the space and we did were awarded the credit without any documentation regarding walk-off mats.

Thank you both for your answers! I am going to go with Michaels option and see what they say. I can only affect the entrys within the project scope. The tenant is willing to do what it takes.