Kitzy is a Ragdoll, who weighed 19.5 lbs when we got her, and hardly ever played with anything. She now is down to 16.5 lbs, and plays a lot more, and even runs sometimes. No problem jumping up onto our bed, or a chair.
For anyone who is interested; the carpet samples are 18 inches by 27 inches. The shelf structure is four levels spaced about 16 inches apart. It is 6 feet tall, and 5'-6" wide to more or less go with the size of the window. I had some scraps of plywood that I used for the shelves, and I sawed the uprights to 3-1/2" wide, and the horizontal members 2-1/2" wide. Each shelf has sides on three sides.