Back in the old days, each and every house had a soil and vent pipe open to atmosphere. The vast majority of these systems are still giving good service and need no attention as there . I can, however, see a slight disadvantage in having such a system in that each house will have an inside pipe that becomes an outside pipe with associated thermal bridging, whether the stack runs externally or whether it runs internally and up through the roof.
Nowadays, it is common to have fewer open vents than houses. Those houses that do not have an open vent will have a 'durgo' or AAV at the top of the soil and vent pipe. This works until the valve fails and a smell comes up through the faulty valve. Provided there is easy access to replace the valve, and people don't do idiotic things such as box the valve in where you cannot see it, this is not a problem. But the system relies on the fact that at least one house (or more if required at design stage) has an open vent, and some people just don't understand this.
Part of the problem is the (probably unavoidable) grey area between what work really needs a dedicated plumber and what does not. Obviously a general builder could construct a perfectly functional drainage system, but this relies on a fit for purpose building control system, which the UK currently lacks. As others have noted, private building control inspections often lack substance.
