Adding bathroom above existing - offset walls

[PaulDIY]

Hello Everyone,

I'm considering adding a new bathroom above an existing bathroom. I live in a cape cod so the upstairs has slanted ceilings and 5' knee walls. The issue I'm running into is how the bathrooms are stacked, the lower bathroom has the wall with all of the vertical plumbing components under the middle of the upstairs room. The vent 90's across the floor between joists before going up and out the stack in the crawl behind the kneewalls. I want to reconfigure this layout by replacing the vent stack and converting it into a drain for the upstairs bathroom group. I will then reconfigure the downstairs bathroom group to combine the drains in the crawl space below it. Can someone take a look at the attached drawing and let me know if this is a reasonable way to lay out the two bathrooms? I live in Ohio, 2021 IPC codes are the standard.

Thanks,

 

[Tuttles Revenge]

Both bathrooms look to meet horizontal wet venting rules as far as layout.

I'm not incredible with IPC but the things that may not be necessary:

1 downstairs bathroom; the vent pipe downstream of the toilet seems to be not needed since the sink is venting that bathroom group.

 

[Sponsor]

 

[Jeff H Young]

works on paper if joists and framing allow. dry vents can be 1 1/2 if you care to

 

[John Gayewski]

The drawing looks fine. There are some inefficiencies with the piping, but it should all be legal as drawn.