Is it possible to slightly reroute a drain/ vent in order to conceal it in the exterior wall?

[MiniMe4Eng]

As you can see in the picture I am changing the position of the bath tub and the position of the sink.
After asking around here I have come to the conclusion that I probably have a drain and a vent somewhere in a wall that I was planning to remove (shown replaced with a pane of glass in the second picture)

The third picture shows what I am assuming is the drain that I would like to reroute in order to conceal it in the wall for its basement portion. Is it possible to install a fitting that would push the lower segment of the drain into the exterior wall? so I can hide it ?

I am planning to hire a plumber for this (not sure how expensive and difficult this should be) but before doing that I want an engineer opinion on the pros and cons for doing this
Any help will be much appreciated

Here is the current layout

and here is the new layout

and here is how I believe that the drain is positioned
it also explains the existing wall between the toilet and the bath tub
this wall is blocking the light and it uselessly segments the space in the room

Update after demolishing the wall between the toilet and the sink

Existing route for the pipes

New route for the pipes
so basically I would like to runt the drain and the pipe along the wall and then when they reach the floor
reroute them back to enter the floor where they used to. I will conceal that in a box that will sit between
the toilet and the bath tub. (the brown box in the picture)

 

[dauwerda]

Each bend in the main vertical stack (you would be adding 2) will require a vent just below the horizontal portion - this is to ensure proper ventilation in the event of a clog due to the change in direction of the stack. However, this doesn't look like it will be an issue as there is already a separate vent line there that you are also rerouting (provided it is large enough in area to meet code).

 

[MiniMe4Eng]

Do you foresee any functional issues due to this re routing?
I am being told that it might not be OK to run them across an exterior wall

 

[dauwerda]

I'm not sure what the code requirements in CA are, but in the US it is frowned upon in freezing climates, but its not entirely prohibited - there are some caveats that go with it. See below for the IRC code excerpt:

The other consideration is how much of the wall you are allowed to drill/notch to allow for the stack to pass through the top and bottom plates of the walls. The top plate is most likely a chord for your floor diaphragm so you will need to make sure it is still structurally adequate to perform this function after all is said and done. If you have the space, it would probably easier and cleaner to frame a new wall inside the exterior wall to contain the plumbing - this would move your tub 4" further into the bathroom.

 

[MiniMe4Eng]

The last picture shows you that the bath tub is not reaching the pipes, it is too short and it leaves me room to build a box there to hide the entry points in the floor
I would be happy to make a vertical box to cover the pipes provided that they can be run along the wall vertically
There is already a niche there formed by the space where the toilet is installed, as you can see in the picture below (see the dotted surface)
That is where the framing stops because I guess the contractor was lazy and he did not want to relocate the toilet properly when they finished the basement

So my idea is to move the pipes there .
Not sure if I should post a new thread ...I have some structural/framing related questions ...I opened up the ceiling and I now have a clear picture of how the joists were done and I need to know if I can change the things a little bit up there

 

[dauwerda]

Oh, so the lower bathroom is in a basement and the upper is a first floor - I thought it was 2nd floor and 1st floor. So your intent is to keep the pipe inside the basement wall and conceal it with interior framing that is used to finish out the concrete or block basement wall, correct? This shouldn't be near the problem of embedding the pipe in an exterior wall (where the pipe runs between studs and does not have any insulation between it and the outside wall sheathing).

 

[MiniMe4Eng]

Yes you are correct
The end result should be this
Not sure if I want the glass between the toilet and the bathtub
There should be some magic that the installer should do in that grey box ...that if I decide not to open the floor to do the things properly
in which case that box won't be there anymore, just the vertical one that hides the pipes