Not all tiles will be pillowed, it's just something to look for, especially if they'll be on a floor. If they are pillowed, you'll end up with the most lippage if the midpoint of the long side meets the end of a tile, so a running bond would the be worst case scenario. A herringbone pattern would do the same. Not sure what you mean by "diamond" pattern for a 12" by 24" tile. Though set straight in line with a wall or on a 45-degree bias, it's all the same, it's more important how the tiles stack against each other versus how the pattern is oriented/aligned with to the room's walls. Again, it doesn't happen to all tiles, some are indeed flat. Starting several years ago I started doing more large-format with the 24" tiles, that's when I noticed it. It a 50% offset running bond it'll be the worst, as you'll have the high midpoint of a pillowed tile right next to the lower ends of the adjacent tiles. Less so with lesser offset, like a third offset. With a stacked pattern lippage will not be a problem. Didn't mean to throw scare into anyone. Just something to consider when thinking about tile size versus location (wall or floor) versus pattern.

is the large cabinet staying? the bathtub is staying and youre tiling the surround? can we a pic of it? (does it go to the ceiling, the tile? do you want a light over the tub?) the current lighting is really dim. is that changing? is there a ceiling light? I ask because this affects the tile choice too. doing a large tile on your floor would be a waste because of all the cuts. Which is fine, but just know that you'll only need about 6-9 of those large tiles. I'd do an 18x18, or a 24x24. to give you an idea, this is my neighbors 5x8 bathroom. She wanted a shower only so we took out the tub. The floor tiles were 24x24 and I think I used 6 of them. She wanted the bold print tile on the one wall and the subways on the other. the shower floor is an elongated hex this is another one. super small the sink is behind the door. We put in a pocket door and the owner got a floating vanity he liked the marble mosaic for behind the vanity (which BTW, always try and do a wall mount faucet. it frees up more countertop space) owner borrowed some space from the garage and pushed back the shower Tile floor in there is a porcelain charcoal herringbone, and the outside tiles were a 12x24 porcelain in a deep, dark charcoal or Anthracite. I'm showing you these so you can see what different shapes look like in a small space similar space to yours w/a 2" black hex floor and white 3x6 herringbone subway tile wall and shower I think you could do a scallop in the shower, or even on you floor. (have you seen Tilebar.com new scalloped tiles?

Dear Weedyacres: One bedroom is 13 x 25, the other is 12 x 18. The other bathroom which is not in the drawing serves two bedrooms and one of those bedrooms is really tiny. On the other side of it is the dining room, so no way to make that smaller. I guess the only possibility at this point would be to loose the tiniest bedroom and turn the current master bath into one with the spiral shower, but I don't like that idea at all because we mostly heat that part of the house with the fireplace and I wouldn't want to loose a bedroom in the main section. Plus I think that really might affect resale value. Probably best to leave as is. I am so thankful for everyone's input because I think it's helping me to see that the spiral shower is a no go. Actually, the house isn't the main feature for me. The main feature is the two acres and lots of woods and the sun room with wall to ceiling windows. And the room we will use for dancing which actually brings me to another problem. The house is on a slab and we want hardwood. Sounds like engineered is the only way to go. We keep this room about 50 degrees and we want something that won't hurt our feet like tile would do. Thanks again for your help. I really do appreciate it very much.

I agree I love large format tile but not that tile in that small space . BTW you need a real good tiler to even tihnk about installing that size tile anywhere. IMO the biggest tile you can do would 12 x24 You do know everything has to come out of there before tiling .