The first picture is our old bathroom before demolition. The lower ceiling on the left is ductwork which can be seen more clearly in the post-demo pic. We are switching from the large jacuzzi tub/shower to a curbless glass shower. Originally I wanted the shower head on the right hand wall since left to right is a longer dimension than front to back. I was told I can't put the plumbing there because it is an outside wall. The GC wants to put the shower head next to the ductwork where it was before. I am worried that the dry wall around the duct will get moldy and damaged from the water and humidity. Should it all be tiled? How would you design this shower?