Im planning to add a 2nd bathroom to our home. Although Im an architect, I havent been around the bussiness for a long time so my plumbing knowledge is a bit rusty. My main concern is the ventilations required for the new drain net. Basically all the fixtures: Sho- wer, toilet & sink (in that order) are going to be po- sitioned along one of the walls. The main drain line is going to be parallel to that wall, somewhere in the mid- dle of the bathroom starting at the shower, receiving the toilet drain, then the sink drain and connecting to an existing 4 dia line. Since the drain of the shower and the toilet are going to travel away from the wall, do I need to ventilate those? and if I do, how it is done?. Can you recommend any book or publication cove- ring that topic. All the books on bathroom remodeling are not specific on this issue.