I just finished an addition to my twenties home. I tried everything to get a bath and closet with in a 13 x8 ft space but everything felt cramped and instead of having a tight closet and a tight bath with small shower and vanity we decided to add wardrobes to or large bath. I wanted custom but due to an unexpected health issue we scaled back budget and went with IKEA pax wardrobes they hold all of my most worn seasonal clothes and all of my husbands work clothes plus most worn casual wear. I like the reach in better for organization too. We still have the orginal reach in closet and a pine older armoire for extra items in the bedroom but never open it. Could you add wardrobes in the bedroom and have a nice sized bath with additional storage? I really love my large bath after years in this old house with tiny baths and closets. I was unconventional and like keeping my clothes in the bath which has two venting fans. it is my most private from the street area in my room so it is where I change anyway but the wardrobes take up so little space I could have placed them in the bedroom without losing much floor space too. in your second plan you can turn the vanity and make it longer and have the edge abut the shower with a half glass panel and than the door....

I much prefer the closet off the bath and easy access from the closet to the laundry. Ours is a walk though closet approx 15' x 7' 6". Doors opposite each other giving DH a space of a bit more than 5' x 7'6" and I have about 7' x 7' 6" on my end, so basically two decent sized, but not overly large walk in closets sharing a 3' walk through between the bath and my office (but steps from laundry). DH slept in this morning. I showered and got ready for the day, put up laundry, and dried a load of towels and put them up all without disturbing DH. During the day, I most frequently access the closet and master bath from my office. Very convenient.

Depends on the layout. Our design has a combined space with wardrobe, linen closet, and vanity on one end and wet area (shower, tub, and sauna) on the other. Toilet is in its own closed space in between. It makes a lot more sense to me for the bathroom and dressing space to be combined. Humidity can be dealt with through adequate ventilation (some ventilation fans even have humidity sensors).

We've always lived in very warm and humid southern states. FL and LA were the worst for humidity, but the others haven't been much better. Not once have we had mold in a closet that opens off our bathroom. We use the exhaust fans as recommended and manage the overall indoor humidity to the best of our ability. That means using a portable dehumidifier during the shoulder seasons, which we'd need no matter where the closet was located. The new house will have a whole-house ventilating dehu system. We much prefer a compartmented bathroom and separate closets that both open off the bathroom. If either of us is up late or rises early, the other one is not disturbed. If we need to get ready at the same time, we have more privacy. For over four decades this has worked well for us. Other folks have different preferences, but the negative responses (some rather rude) from a few here whenever these situations come up surprise me.