“Research shows that employees who work on different floors interact 50% less than those who work on the same floor, and the difference is even greater for those working in different buildings,” according to Gerd Gigerenzer in the Harvard Bus. Rev., Vol. 84, Feb. 2006 at 58.
The drastic drop-off in interactions supports the common observation of how hard it is to have lawyers exchange information and deal with each other when the lawyers are geographically separated. If different floors cuts interaction in half, I suspect larger distances harm relationships exponentially more (double the distance, halve the sharing).