I am attempting to redesign a standard 5x8 bath for my parents' home. Currently the room is 5x8 with an alcove on the right side (13"x36"), similar to the bump-out shown. I will be gaining the additional space by taking 13" from the back of a poorly desgined master bedroom closet, as well as removing a linen closet (currently in the lower left) and awkward stubby hallway (currently lower right).
A few points to consider:
My mother would like to keep the operable 24x36 double hung window in the tub area. This is one reason for creating a separate shower.
The bump out behind the new vanity is a mechanical chase and must stay (the chase is currenly behind the linen closet).
The shower head will be on the left side with all other plumbing.
The entire room will be set on a mortar bed (flat as well as pitched into the curbless shower area) and waterproofed with Schluter Kerdi and Ditra.
There will be just one frameless glass panel to protect the toilet from overspray. I am currently thinking of not even using a shower door on the right side - just letting the pitched curbless floor take care of the water. If overspray ends up being a problem an additional frameless pivot door would be an easy addition once the shower was operational and tested.
Now to the question: Is this layout even permissible by standard codes? I have personally never seen a layout like this, where the shower is essentially a "walk-through" type. The only issues I can think being a problem would be accessibility to the tub controls - but that is not a problem since there will be no glass between the tub and shower. One would simply walk right through the "shower" and lean over the tub edge just as they would if the shower was not even there.