I spent the better part of my summer building a catio, which is basically an enclosed patio for my kitties to be able to go outside without being exposed to any of the dangers of being outside. They go in and out through the kitchen window and there is a bolted lock on the outside door so I can sit out there with them. I designed the ramp and enclosed the entire thing in fine mesh screening so that the bugs wouldn't be able to get into the catio or my house. Since I have absolutely no training in building, I spent a lot of hours with pieces of wood in my hand and painting wood while contemplating how to put the thing together. I learned how to use a drill and got to play with my jigsaw a lot and that was always fun. Discovered that an electric stapler is MUCH easier on the hand muscles as well. *wish I had discovered that BEFORE the hand cramps*
I painted the entire thing to match the color of the house, put a tarp on the top, put all season carpet on the perches and the floor, and wrapped a lot of the branches and some perches with sisal rope. Now to figure out how to make it warm enough so they can use it for the winter months! They love it!
It was worth all the aches and pains, the money, the sunburns and the cursing! I hope if you have kitties, it gives you inspiration to keep yours safe as well. It cost me about $1000. to make, but you could make one with no decorations or screening for less than half of that.