Currently we have a one sink vanity and are wanting to do a two sink vanity. Please take a look at these drawing and tell me if either or both will work for the drain. The vent line currently goes straight down and connects to the drain from the sink. The current drain for the sink is out of the wall coming through the floor. The way I want to plumb it now is in the wall with the drains coming out through the wall. This is on a structural exterior wall with 2x6 construction. I believe that means it is ok for me to bore 2 inch holes without having to add extra support. The biggest difference between the two is that I will have to drill an extra hole in a stud for the top picture. That means one stud will have two 2 inch bore holes. The other option would just have one bore hole per stud. For the water lines I plan to just bring my hot an could up through the bottom plate and then tee off of them to have supply for each sink.
In this picture the two 90 elbows that are pointing up would actually be pointing into the the room for the sink to connect into.
In this picture the 90 elbow on the far left of the horisontal line would face into the room for the sink and the first Tee from right to left would point into the room for the other sink connection.
In this picture the two 90 elbows that are pointing up would actually be pointing into the the room for the sink to connect into.
In this picture the 90 elbow on the far left of the horisontal line would face into the room for the sink and the first Tee from right to left would point into the room for the other sink connection.