Hello - I'm attempting to calculate the amount of sf that need to be vegetated for this credit. In looking at the guidelines I need to "restore 30% (including the building footprint) of all portions of the site identified as previously disturbed."

I have the sf for the total campus (hospital, admin building, new central utility plant, and inaccessible cemetery + open space), but there wasn't a building on the site prior to this point (other areas of the site, actually, but not where we're building.

Do I use the entire square footage for the campus in my calculations, or just the open space, or some mixture? I'm new to this and trying to figure out the details. Thanks!