We used 12 x 18 tile with a 1/3 offset. We laid it out on the floor to calculate our rows, starting with the travertine base molding and working up 5 rows before starting our 4 x 4 accent tiles. This left us with about an 11" or 11 1/2" row at the top where the difference is hardly noticeable. We decided that it would look best, and certainly be easiest, not to try to bring this row around to the wall were the tall niche is. Instead, we cut a couple of very large tiles down to a size equal to the accent row so that we could maintain the grout lines. The tall niche was framed in but we didn't finalize the location of the shelf until we knew exactly where the rows of tile would line up. The smaller niche is in our pony wall. As you can see, we put a bullnose on the outside walls of the niches and then cut a tile to line up with it on the inside of the niche walls. I'd prioritize a deeper niche over avoiding a vertical grout line. As long as you have a solid piece, whether it be granite, quartz or tile on the bottom, I wouldn't be concerned about vertical grout lines in the niche. As far as the size of your shelves, I'd want to make sure that my largest bottle could fit with some room to spare. My niches were designed to accomodate my Costco size bottles and I LOVE them! (My son had just taken a shower before this picture was taken so the grout is darkened from the water... not mildew!) I hope this helps!

Thanks for all the replies! I measure our shampoo bottles, the tallest is currently 12 inches, but we do sometimes buy form Costco, so maybe allowing that 16 inch someone mentioned is best. Bill, what are the dimensions on your middle one? It looks fairly tall/narrow, as do igloochic's. I think we'll end up that way, as we'll probably be limited to the 13 inches wide between studs. I think I like the 22-inch tall idea, with 18 in for bottles, an inch for the shelf itself, and then 3 inches for soap, razors, other short items. Anyone see issues with 13 by 22 inch size? It may look a little tall and narrow, and hopefully the 3 inch height is tall enough for short stuff? And good thought to stay on top of them doing it! The designer our contractor has on staff will draw it up for us, including shelf, so hopefully it's then their fault if they install it wrong (and even more hopefully, they'll do it right the first time!)

Well, I am of the opposite view, lol. At first glance I say put it behind the shower head, along to wall near the toilet. Is this your personal bathroom? If it was my personal BR, I wouldn't care if I saw my stuff on the shelf. The reason for the rear wall, is that if it is about 3' or so away from the rain shower head, it will probably stay dry. The side niche might get wet. In my shower I have a niche that is in my 3x5 shower. The front half of the very long niche gets wet, while the back half doesn't. The back wall in my shower never gets wet just misty from the steam. I wipe my niche and the total shower out after every shower with a high quality micro fiber. Because of the higher maintenance I keep 3 items on my shelf. The wall with the niche is 5' long. the shower head reached out about 18" I think. My shower maintenance, I know you didn't ask, but since you're worried about mildew/mold: I only use liquid body soap. I use Soft Soap or Dove. It doesn't build up into soap scum like bar soap. I buy dark washcloths because liquid soaps leave a dark center patch in the cloths, that you can see on white cloths. I don't use a squeegee because its way easier to use a towel sized microfiber. My towel is an auto detailing type white towel, fluffy, made in Korea. I could wipe 2 showers down before I'd have to wring it out. I like to compare the task with wiping a car down with a towel, or wiping a car down with a squeegee, haha. When done, I hang it over the shower door and its dry by the next shower. I wipe all walls, inside doors, and fixtures. There is never any mold in my shower. It looks the same as it did when it went in 3 years ago. I have a good exhaust fan. Since I wipe my shower daily, I never have to "clean" my shower. I have washed the cast iron floor pan about twice a year. I just spray the floor with the hand held from time to time. I am the only one showering in it, and don't have dirty feet :)

One of the reasons that your inspiration photo looks so good is the simplicity in materials and design. 2 materials only. simplify your rooflines / slopes. Stone on first floor and chimneys. Wood everywhere else. Simple, thoughtful and it makes sense. You have SO MANY things going on, there's no thoughtful rationale to have 3 materials. And yes - you need accurate renderings. Preferably with some perspective to get a better 3D feel.