Both get their own commentary box. Sky were to get the old BBC one in a prime posistion, however they wanted a different one in a better location for Martin Brundle. In otherwords they get the one nearest the lifts or stairs. Skys comms box is next to the BBC 5Live box at all but one races so far.
When it comes to segregation, the only thing that Sky was wanting away from was the Itialian and Brazillian comms boxes as those guys are the loudest in the comms aera.
Sky and BBC stay as far away from one another during the race weekend as posible, however recently they have had to come closer in the paddock area. Not next door close, but more 3 doors down neighbours. However the BBC 5Live guys are always next door to the Sky guys as the 5Live guys are freindly with the Sky guys.