A little carpet adhesive, a few staples, a handful of small brackets, and it's almost complete! Overall, it's solid as a rock and has enough mass to keep it stable without anchoring it to any walls.
Only things left are a ramp from ground level to the second story across the front and potentially a hammock somewhere(I'm struggling to see where i could put one without compromising some other useful part of the tree).
I've wanted to do this so badly, but just haven't gotten around to doing it. Partially due to not wanting to spend the money for floating shelf hardware, that stuff is unreasonably pricey
That looks great, and your cat clearly likes the perch ❤️
Maybe it'd like a hangout spot even higher up? I saw a video a while ago where somebody had made a "cat path" high up on their wall with some sort of cylinders maybe 15cm (6") in diameter and max 45cm (18") long wrapped in twine, at maybe 1m (3') intervals or maybe even a bit more, so that the "path" led to a hangout spot high up in the corner of the room. Of course you'd need to build that in a spot where the occasional falling kitty won't land on your collection of priceless Ming vases and live land mines, or your 99" 4K OLED TV.
Wouldn't even need all that much material. Could maybe use pieces of PVC pipe for the "path", twine, that hammoc or whatever platform you'd want to have, and then the… uh, what's the word in English… fasteners? Everything you need to attach all that stuff to the wall.
We've got some of those on the opposite wall, actually. The cats like them, but shelf-type things are better because we've got some fat, declawed cats, so acrobatics aren't their strong suit
Untreated 4x4, which I think cost like......$10-$15 maybe? Then carpet adhesive was like $20, some wood screws, and more staples. I've probably got $60-$90 in it, but it would be pricier if I didn't have the brackets already.
It's hard to say exactly, but I will say that if you bought everything you needed from, say, home depot, it would be very expensive, probably 2-3× a similarly sized store bought model. But the store bought ones are small for large cats, so your mileage may vary