I know you don't want to hear this, but if you're planning on having this as your main bathroom when you get to the point you can no longer climb the stairs, you should install one of those walk-in tubs in case you get to the point you can't stand in the shower. My elder mother-in-law has gotten to the point she's not stable enough to stand, and bathing her is quite a chore for my sister-in-law. There's no way they can put one of those walk-in tubs in without taking down walls and the like, but if there were, I know my husband would do it in an instance. Don't assume you won't need all the senior stuff.