In our new house Monica and I decided to build something to get the cat’s litter box outside. I bought a large storage box you might use for seat cushions, towels, or whatever around a swimming pool. Then I modified it for use as a an outdoor cat box.
Step one, drill a hole in the wall, then use a jig saw to shape up a nice opening.
Now I take some 1×10 and build a box to jam in the wall.
Now I cut from the other side, and cram the box in.
Now I cut a hole in my giant storage container.
Now just slide the storage container over the box, and add a litter box to the inside.
Final step, add a swinging cat door to the inside wall.
This whole deal seems to have worked out pretty well. I have more to do, but it’ll work for now. Next I’ll add a light to inside of container, and I’ll paint the wood and maybe build a platform inside the container.