Walk off Mats for Residential Units on ground floor

The BD+C reference guide states "For Option 1 Entryway Systems, the systems are required only at the ground level, for each residential entrance from the outdoors."  I have been involved with a few LEED v4 NC residence halls on college campuses and they located entryway systems on ground floor units that had an exterior entrance. Fortunately there were only a couple of such residences.  Lately I have been substituting the v4.1 EQc Enhanced IAQ Strategies credit since the options are more flexible.  My guess is that gbci will not allow you to substitute Homes / Midrise requirements on a project pursuing NC. On a past LEED for New Construction project, I used the construction waste "weight-to-volume conversion table" located within the LEED for Homes reference guide, and gbci would not accept this calculation method on my NC project. Unless others on LEEDuser have learned otherwise??? I have not had much luck substituting from other LEED rating systems. 

WE've been able to swap in the v4.1 Multifamily acoustic credit in a v4 NC multifamily project.  I recall also being able to exclude hall director apartments that had direct exterior access from entryway mat requirements on a dorm project. But that was v2009 and those apartments also had hallway entries so not a perfect equivalent. But, worth asking! 

Dear iris, dear everybody,  Please, how do you contact GBCI for their advice on technical matters? is it mandatory through CIR which costs 250 Dollars or is there another free way? Thank you for helping us

Dear Iris,  Many thanks for your quick fedback. It's very useful.