[Freddiy]

Jnaas2, This makes a lot of sense. I've updated the plans as you suggested. See attached. I will route the shower drain pipe over to the small wall next to the toilet. This is dead space behind here anyway. I can then bring the vent up vertically from here and tie into the existing vent behind the toilet as originally planned. Since the vent piping is now above slab I also reduced the vent size to 1.5" pipe. Great suggestion on building a box to not fix the shower location until I get the shower itself.

Another option I was toying with before I started this post was to not add the extra vent for the shower at all. To do this I would have tied in the shower just downstream of the existing wet vent tie-in. That way I would have both the toilet and the shower wet vented from the existing vent. However from my research I found that a 2" wet vent is not large enough for both a toilet and a shower. Is this accurate? Eliminating this extra vent would make this a lot easier.
Thanks Fred