It's hard to run a drain horizontally in finished space. In unfinished space it's not bad. Vertically the drain can run through any wall.
Will you have an unfinished basement or crawlspace? Put the plumbing fixtures where you want them, run the drain down through a wall and across the unfinished space to join the existing stack.
If you don't have an unfinished space, in order to run a drain perpendicular to the floor joists -- which usually run the short dimension of the house -- you have to run the pipe below the ceiling below and then box it in with drywall. Usually you try to do this either in a closet or behind cabinets or something like that, this is where an architect can really help.
Making a hole in the brick for a drain pipe is not a big deal.