We're in a region which allows single stack DWV installations in multi-storey buildings. In other words, a single large-diameter vertical pipe that serves as both discharge stack and vent for several floors at once.
For example, our plumbing code places limitations on the number of fixtures that can connect to the stack per floor (typically two bathroom groups per floor), the maximum length of fixture discharge pipes connecting to the stack (2.5m), and the total number of floors a stack can serve (maximum five floors). That's about it. No trap vents, no branch vents, no dedicated vents. Pretty simple right?
However, I understand that most regions do not allow this type of installation and I was wondering why. What do they know that we don't? Will we encounter problems with this type of installation even though we're staying within the parameters defined by our plumbing code?