We have decided to add a bathroom to our basement which has toilet, water and bathtub drain already roughed in. There are a few constraints.

1) There is only 1.5" drain and per code it needs to include a bathtub. We can't just put a shower there. But the space is a bit tight for a bathtub, so I'm really struggling to figure out what to do. Ultimately, we probably need to get a small bathtub, no matter how we go about things. Most bathtubs that you can use for a shower are alcove and so you have to build in a little half wall-- that's the 6" thing on there. We could rotate the tub and it gets more space but then it is more awkward because it clips the window. There is a neighboring bedroom, we could knock down the wall and moving the piping over, but that's kind of pricey, so I'd like to avoid that.

2) we have the access (in brown on the floor plan) for our sewer line for maintenance and we cannot move it but to face different directions, but it needs to be directed away from the toilet. But this also means that we can't put a shower where the toilet is, cause the area can't be blocked.

3) the toilet needs to be on the left upper side of the floor plan ideally, although we could probably move it down, it'd just be more piping for the water.

Question: any thoughts on how we can design this differently? We considered a corner tub but those don't actually help that much for space because they are very large and uncomfortable. We considered a small cast iron tub, but honestly we hate showering in a cast iron tub. We are imagining it will be mostly used for showers since it is in the basement.....

I'm not sure how much work it would take to make the drain 2" rather than 1.5" but I suppose it could be a lot?