I have been working on an upstairs phase II project (finishing out an addition). In my head, for some reason, I had decided I shouldn't span the structural beam with a room (any kind of room). I had it in my head I should put a wall across the beam, only. (this beam used to be the exterior wall. When we added on, we replaced the wall with a beam to open the downstairs kitchen/addition to great room. So, the beam would be in the floor of any proposed phase II room).

Then, I pushed my boxed boundaries, and I have 2 plans I really like for my upstairs, but both have a "room", and in particular, a bathroom, that has both old and new space.

To picture better, one bathroom in one plan has all the fixture plumbing on the old house side of the beam, and mostly flooring on the new house side of the beam (and a bit of the shower--but we plan to use a cast iron or cultured granite/marble pan, not a tile pan).

Was I right or wrong to think that spanning the old and new spaces with a room would be a bad idea? Or, will crossing the beam with a room/floor be okay?

Will settling be an issue? (the beam/addition was almost 2 yrs ago...but things settle forever, right?) Assuming I don't use Tile floors/shower pan, will this plan be okay? (I would still assume, with tile, any settling that might happen, though we haven't seen any, would mess up the tile.)