Bathroom Design in 3D
Most of a bathroom is finished before the first tile is cut. The membrane, the blocking behind a towel bar, the fall to the drain (about 1/4" to the foot), the niche framed between 2 studs. Turn this one around and step it forward from bare board, and all of it is on screen in the order it goes in.
The buttons step forward through the finishing, from the board up. The ceiling is left off so you can see in.
One click needs a word of warning. The panels that show up at Subfloor are a basement detail, a strand board face on a dimpled mat that holds an air gap over cold concrete. Upstairs you already have a framed floor under you, so the tile goes straight onto the board and that click does nothing. We have left it on the model because a basement bathroom and an upstairs one are two different jobs underfoot, and it is easy to price one and build the other.
Where the wall behind it comes from
Behind the board a bathroom is framed like the rest of the house, so there was no sense drawing it twice. The basement model takes a wall apart layer by layer and it is the better place to look at framing, batt insulation and a vapour barrier.
One thing worth knowing before you go and look at it. That one is a basement wall, and it is built off concrete, so it carries 1 1/2" of rigid foam and a treated plate. An upstairs outside wall is framed, and it takes batt and a vapour barrier and none of the foam. An upstairs wall between two heated rooms takes neither one, because there is no temperature difference across it for moisture to follow. One bathroom can easily have all three of those walls in it (a main bath on an outside corner usually does).
So this model starts at the board and goes up from there.
Why there is no return grille
Step to Trim and a register shows up high on the wall. There is no second grille down by the floor, and that is on purpose. Most rooms get a cold air return, because a room you can close the door on has to let the air back out somewhere or it pressurises and the supply stops delivering.
A bathroom is the one room that does not get one. The return side of a furnace is under suction and it feeds the whole house, so a grille in here would pull the moisture and the smell off a shower and hand it to every other room. A bathroom gets an exhaust fan ducted right outside instead (not into the attic, which we find more often than we would like), its makeup air comes in under the door, and that is why a bathroom door is cut short at the bottom - worth remembering when a new tile floor goes down and somebody trims the door to suit it.
A curbless shower moves the waterproofing
With no curb to stop the water, the shower floor and the room floor are one surface, so the waterproofing has to be one surface with them. It runs up the walls, straight across the shower floor and bonds to the drain flange, and the fall is built into the pan underneath it. The niche gets the same treatment, sill and jambs included, because a hole in a wall at chest height with a shampoo bottle standing in it is the likeliest place in the whole room for water to get behind tile.
All of that happens before a tile is cut. Step to Waterproofing and you are looking at it, step to Tile and it is covered for the life of the room, and the only way back to it afterwards is to take the tile off.