How do I route plumbing vent line around a corner?
Vent lines have to be &quot;vertical&quot; (where vertical is defined as 45 degrees or more, rather than what vertical normally means) until they are &quot;6 inches above the flood rim of the highest fixture on the floor served&quot; so the horizontal routing evidently below the sink level shown is not going to pass inspection, AFAIK.
You would have to run up at (at least) 45 degrees to the appropriate level before you can go horizontal.
The framing there looks like you would have major issues keeping it concealed in the wall. I gather that the &quot;floating&quot; nature of the new vanity prompts the desire to conceal the pipes differently. I'd strongly suggest considering a vanity that does not require structurally difficult rework - or else going straight up the wall cavity and doing the cross connect above the ceiling.