Solar tube to bring in natural light rather than a window? I don't think there is anywhere else to put the shower that size with that size bathroom. You could also try a clerestory window above the shower/linen closet.

Yes, it's the master bath, we want/need a tub in there. The space is large (11'2" x 14'2") , so I'm not sure what you mean by a space this size? The current layout has a lot of wasted space on the closet/makeup vanity side, as there's a pocket door going into the bath/shower side. The Drywall "box" is also wasted space since it was built out only to fit the garden tub/vanity. I was thinking the new shower and tub could expand into that whole wall, which would then easily fit a large tub and a large shower, but I'm a little stumped on the best way to do the remaining layout. Thanks!

needs a littlle more attenyion than just the tile, heating and paint. Are you really lovin' that tub and tile surround???? One note of caution with the heated floor and tile installation. Lay down the heating material on the entire floor. Saving money by only heating a 'path' will result in uneven floor tile. Just a little uneven edge on a tile is a pain on a tiled floor. This is a bare feet nuisance easily avoided.

I would shrink the hall closet by about half, move the bathroom entry door to the right, and build a tall linen closet between a small vanity and the new wall…if there is enough money.