* different wings on the same building, in rooms that are separated by more than 300 ft
* different floors on the same wing of a building in rooms that are horizontally offset by a minimum of 70 ft with fire walls between the rooms that are on different floors
* two rooms separated by another room, leaving at least a 70-foot gap between the two rooms
* there should be a minimum of two separated fire walls and on opposite sides of a corridor

Geographic redundancy is used by Amazon Web Services (AWS), Google Cloud Platform