< Is this model being created using Grasshopper in Rhino?
No it's pure Moi :)
I have emulated an Hyperbolic paraboloid facade ;)
So I will find another trick if there is no easy selection :)

Another tricky selection will be select faces with the same surface but alas in this case above
all faces are different! :D

I return study to my screen :)
Maybe selection by colors will be fine