COMMENTS:
The room is slightly out of square. The sink-counters are square with a base front-to-wall of 18 1/2 inches, and the wall-to-wall left-to-right is 92 1/2 inches. But the south sink (left side in the drawing) is not quite orthogonal to the mid-wall between it and the tub. Perhaps the preference should be to lay the tiles parallel to the base of the north sink (right side in the drawing) and cut the tiles as needed to fit against the mid-wall and the south sink.
The plan is to have a design of small tiles in the middle of the floor between the sinks. The floor, left to right, should be centered between the sinks, and between the tub and the opposite wall's mop board.The pattern on the sink side should meet the one on the tub side at the end of the tub. Thus the two halves, front to back of the room, will be shifted about 2 1/2 inches where they meet, as shown by the grid.
The walls at the head and foot of the tub should have tiles to a height several inches above the height of the tub. This will protect the wall from moisture damage as shown in the photograph on the first page. We plan to keep the existing wallpaper. We have extra to take care of any areas where replacement is necessary.