After 4 years of living together, my wife and I couldn't decide if we should adopt a cat or a dog. She is a dog person and I definitely am a cat person. Starting here, we had two options : adopt a rabbit or adopt a kitten AND a puppy at the same time. We don't like simplicity.

We live in a 50m2 appartement. To let everyone have enough space, I wanted to build a dedicated ground for our kitten. Like a cat tree but bigger.

Another problem was the spot to the kitten litter. The only place available for it was our living room, but we (and our guests) didn't want to see~smell it each time we enter the room. My tree will should handle this for me.

So I started to make plans.

Supplies

Wood (all size, all shape)
Sisal rope
PVC tube (like for gutters)
Hose clamps
Angle brackets
Flexible fences
Carpet flooring
Staples
Hinges
Screws

Step 1: The Base

The base is a quit simple box, opened on one side (on this side will be the future litter door). One of the feet will be the spine of the tree. Later, platforms will be attached on that spine.

I used two panels for the sides and one other for the top. I was running out of panel for the third side so I used some spare wood-panel.

The carpet coating was a long and complex step. I bought about 2m x 4m of it. I cut it with a cutter blade and I used a lot of staples to fix it on wood.

Dimensions of the base box are approximately 65cm wide, 50cm depth and the height is enough to let the kitten litter enter inside.

I wanted to add two platforms to let my cat clim the tree. I estimated distance between each to approximately 30cm. And 30cm more for the bottom house. So, above the base, the spine measure 120cm. Those 120cm will be fully covered of sisal rope.

Step 2: Bottom House

This is the first place were the cat could hide himself. I wanted it soft and warm :)

Dimensions of this box are approximately 65cm wide, 40cm depth and 30cm in height.

There is a front door in the middle and another opening on the ceiling. I cut them with a jig saw.

I added carpet inside the box and then I fixed it to the base from the bottom.

Notice the three angle brackets on the top, they will help us for the next step...

Step 3: Gain Height

To create the cylinder part, I used a PVC pipe. I cut it to 90cm to be as tall as the wood spine.

I used hose clamps to fix it to the bottom house. Sisal rope will hide those metallic parts soon.

I used some staples to attach the sisal rope under the pipe. When the pipe is in place, I started to roll it around the pipe.

Step 4: Platforms

You can see on the first picture, the two platforms I wanted to install waiting to be installed.

The lower one is juste a quarter of circle with a square cutout to be fixed against the wooden spine. Notice how I set two angle brackets at the right height. Be sure to install those bracket before rolling the sisal rope AND the carpet. Like this, brackets will remain invisible.

The highest one has a funny shape : it's a composition on two circles of different diameters. I cut a hole in it to let the PVC pipe go through it. To fix it, I used 3 angle brackets, screwed in the pipe and another hose clamp. This platform will allow my cat to reach the final stage of this house. To do so, it will be slightly oriented to the front, to help him to reach the last floor.

The hard part was to build those parts in the same time I put the sisal rope on the PVC pipe.

Platforms are two face carpet covered. In order to keep angle brackets invisible, I cut the carpet just around them, I fixed the screws then I used double-sided tape to put the carpet over it. I did the same with the top house.

Step 5: Top House

The top house is the most luxurious spot of this building.

Assembling the wood was not so difficult but cover it up with carpet took me a lot of time.

The two holes are special spot for the kitten food and water. It's a multiple purpose idea :
- My puppy will not be able to eat the kitten food
- Food bowl will be invisible from the bottom
- It will force the kitten to use this palace or die of hunger

It was at this moment, when I put the top house above the rest of the tree, that I told me that maybe I see it too big. It's only few cm of my ceiling.

In order to keep angle brackets invisible, I cut the carpet just around them, I fixed the screws then I used double-sided tape to put the carpet over it.

Step 6: The Shelf With Tunnel

The shelf itself is juste a plank with a hole, cover with carpet. I cut rounded edges to make it more pretty.

The tube is made with flexible fence. I maintain it in place with wire. I used the same wire to fix the carpet in place.

To assemble those two parts, I used a small piece of wood inside the tube to let screw pass into it and reach the shelf.

Step 7: The Litter Door

The litter door is another plank carpet covered. I used hinge on top to allow me to open it to grab the litter box.

I also added magnets on the bottom to prevent the door from opening too easily.

I managed to cut a hole in front of the plastic door of the real litter box.

Step 8: The Hammock

I founded a cat hammock on a flea market. It was great but it was gray. I sanded it and paint in white. I also replaced the original piece of cloth by a larger white one. Two more angle brackets and the hammock was on the wall !

Step 9: Conclusion

I built this tree about 2 years ago. I moved in a new place and moving those tree wasn't really a piece of cake.

My cat loves it. He loves being in height. He is always on the shelf or in the top house (he sometimes climbs on the roof of the house)

I've seen him using the hammock only once or twice, I didn't install it in my new home.

I'll be glad to share with you advices or tips if you want to build your own. Please, ask what you want in comment, it will be a pleasure to help you :)