If you're one of the humans lucky enough to be owned by a cat, you obviously know they bring a fair amount of supplies with them when they move in. Toys, beds, trees, perches and all that are harmless enough, but what can you do about the litter box?

It's fairly bulky, leaks litter when the cats hop out, and you don't want it near the flow of normal household traffic. In our house, we had it sitting in a spare bathroom until we needed it for guests. Rather than have our friends suffer with sandy feet, we decided to move it to a closet.

This project requires a self-contained closet that has an internal wall that is not shared with the door. Ours was on the inside of an internal hallway so we had two sides to choose from. Aside from that, you'll need some simple trim material, carpentry skills and a few fasteners of choice.

Step 1: Cutting the Hole

This project isn't much more than making a hole in the drywall and framing it out. Begin by deciding on a location and marking out the size of the hole. This will be dependent on the size of your cats but remember to add 1.5" to the total size to account for the trim material (I used a pine 1x6).

The bottom of the hole should be flush with your trim molding. If possible, ground one side to a vertical stud to anchor the parts. Mark the lines to be cut, start them, and check for electrical wires/pipes/etc. before continuing. Once you are sure you are free of obstructions, remove the remaining pieces of the wall with a drywall saw or other tool as appropriate.

Use the outside hole as a template to continue on the inside. Mark the corners and remove the inner layer of drywall, making sure everything is square.

Step 2: Framing

Measure the total thickness of the wall (stud + 2x layers of drywall) and rip your trim material to this width. Cut two pieces to match the top and bottom widths of the hole. If you're good they'll be the same :)

Sit them on the top and bottom of the hole and use some finishing nails to tack them down. Toe nailing to the adjacent stud helps as well.

Continue by cutting the vertical parts for the sides and nailing them in place.

Step 3: Exterior Trim

For the outside, you don't want an unfinished hole punched through your wall. Take a trip through your local home store and find some molding that somewhat matches what you've already got installed. Cut it with a miter saw so that it sits flush with the molding on the bottom but is slightly wider than the pine trim all around the sides and top.

If you look closely at most wood door frames, there is a 1/8"-1/4" reveal around most door frames where the molding meets. Why? because if it was flush, seasonal changes in the humidity would constantly cause the paint to crack and be extremely noticeable and necessitate adding paint/filler. With the reveal, this becomes less noticeable and adds to the architectural detail of the frame.

Once the parts are cut, glue them down and add a few nails to hold them in place.

Step 4: Shelves

The internal shelf is straightforward for most woodworkers/carpenters. Mark the top of the litter box so that your shelf clears it and use a level to extend the line around the interior of the closet. Use a stud finder to locate solid anchoring points for the shelf supports.

Use some of the leftover 1x material to make small supports ~1/2" thick and screw them in place around the walls, making sure everything remains level. I started with the middle of the back wall and worked outward from there.

Likewise, cut a piece of plywood to sit on top. The only trick here is to not assume your walls are square; mine changed by 1/2" over the 18" depth on the right side. If one is available, use a T-bevel to mark the corners and a jigsaw to cut it out. Sand/paint as required and sit it in place.