I am having a licensed plumber do a new bathroom. He is a good plumber, but somewhat unimaginative. There are some quirks involved and I would like to have some ideas and options to offer him.

In the drawings below, the blue wall is an existing concrete block wall. The red is a concrete footing. The green is a soon to be poured concrete slab that is a new bathroom addition. There will also be a 2x3 (3" finished thickness) stud wall against the concrete block wall.

The issue is that the footer extends out 5" past the block wall. What is the best approach for getting the toilet and vanity vents into the 2x3 wall? My only thought is a couple of 45's. Since the floor is just 4" thick, even 45's might stick up out of the floor a bit (but it may have to be).

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