[Porsche-O-Phile]

Honestly I think that's a bit of a cop-out answer on the part of your architect but maybe it's different over there. Something like that which would have required such a steep driveway (whether 21 percent or 21 degrees, it's still awfully steep) should have been brought to your attention and discussed. I'm not saying he's at fault, but it's something that I'd have definitely brought up in discussions with the client to go over the design and confirm that everything was okay to proceed before going to bid or into construction.

You mentioned an underground garage so I'm assuming the driveway in question slopes towards the structure. Are there provisions to drain water, snow run-off, etc. before it all ends up cascading into the garage? Trench drain? Cross-slope of some sort? It'll be very disappointing to see lots of water flowing rapidly downhill into the storage bay for your 911 if this hasn't been accounted for.

I'm really curious to see how this turns out and to learn more of the details...