Here is our bathroom BEFORE. Please note the litter box beside the toilet. The food and water for the cat are hidden by the vanity, but they are to the left.
Our first step was to find a litter box that fit in the vanity. In this case, we had a short Ikea bin (Trofast, in green) that was a good size. I took everything out of the space under the sink and hung a nail for the litter scoop.
I was set to use a Sawzall on the wall of the vanity to make the cat a little open hole to hop through. Then my husband got home and said I should do it on the back side (the one you see from the toilet, not the room). He also said I needed to put a cat door in the vanity, and if I was doing that, I might as well put it in one of the doors.
So we ended the night with me choosing an inexpensive and not fancy pet door on amazon and waiting. I introduced the cat to the new litter box and took the door of the vanity off so none of us would close it by mistake as we waited.
The cat door arrived and I eagerly measured and cut and installed the door, then brought it to the vanity to test it.
When it swung in, it hit the lip of the litter box! No swinging!
So now we have a vanity with a hole in the door that is cat-sized and she can use. I may have to paint the cut edge. We also have a lot more open space in the bathroom and less of a smell in there.
All in all, I am really quite fond of all the new space in the bathroom, and the lack of litter being dragged on her paws next to the box.
And yes, next time I will measure the door against the vanity before I cut and make sure the height is correct.
****UPDATE: She can't get in the door! It has been removed until further notice. Oops.******