open vented soil pipe

[plumb_know]

doing a new build, built between 2 existing properties. From my study days i seem to recall that only 1 in every 3 properties need to be open vented soil stack and the property at the end of the drain line. Is this correct or have i made this up. i have tried sourcing the answer online but cant find much on it.

help greatly appreciated

 

[ShaunCorbs]

Correct aslong as there on the same drainage run