Caswell Hall has rooms with private bathroom.
Watch the first minute of https://www.youtube.com/watch?v=Yf7BKC79V48 and you will see the private bathroom.
Mouse over https://reslife.brown.edu/residence_halls/map.html and you will see several dorms have rooms with private bathroom. (very stupid map, you have to close the description window yourself)
If you are curious about WaterFire Providence®, watch from 33th minutes.
Those two girls in the video are PLME. They also have a video about PLME.