bathroom plumbing advice please

[diydzindzis]

Hello,

Renovating downstairs bathroom, we have changed the layout and I just wanted to confirm if what I want to do is appropriate.
I want to avoid any gurgling and siphoning. And there is no pretty/accessible space for me to install AAV (maybe under the sink) so I'd like to try without it but if I must can you please point where it is best to fit?

this is the proposed ground floor layout:

original 32mm waste capped off

piped up like so (in subfloor - crawlspace)


Originally the WC was directly on top of the incoming 110mm soil pipe with basin and shower connected to 32mm waste going out under the floor and buried. We didn't use the facilities so no clue if there was a previous problem.

From what I gather the new shower will need 40mm min. pipe size so I am going 50mm.

I also want to avoid digging outside to add extra sweeps.

I think the soil stack on the right should be sufficient venting for my setup but not 100% sure. (about 3.5 meters away)

Any tips / recommendation?

 

[ShaunCorbs]

You will be too high for the shower if the toilet tee is in vertical orientation so you will have to boss it in below etc

 

[diydzindzis]

Soil comes into the building at 45. I was planning to make it vertical-ish in subfloor. I can come out of the ground a little more and make it horizontal if that's better but then do I boss it from sides or from top?

I've read online that WC has to be last or all come in at the same time. Does my solution not achieve it?

Or even other suggestions seem to be to boss it to 110 soil at top upstream of WC. (All the way to the right)