My catio is essentially a one-off. It was a 3 season's porch, but I modded the HVAC that was just behind the wall so it became a 4 seasons porch, and then I had the windows modded so the structure is essentially 80% window, floor to ceiling, with removable screens on the outside. On the inside I installed moveable, removable, louvered glass slats. In the spring and summer I just remove the glass slats so the it is as open as possible. In the fall I re-install the slats so the wind coming in is limited as its gets colder, and then in the winter I close the slats completely with a gasket and they seal against the cold. I replace the screens on the outside with storm windows and it creates a well insulated dead-air gap double pane window. The HVAC keeps it a reasonable temperature throughout the year when it is too hot or too cold otherwise. Normally access to the 3 season's porch was a sliding glass door (which is a good indicator that the 3 season's porch was a late add-on in more recent decades) but I modded it so that it has a cat-door that easily lets the cats come and go as they please without compromising the environment of the house. It's quite sizable, probably about 200 square feet. It is decorated with several cat poles and other sitting spaces, cat beds, water, litter boxes, dry food feeders, etc... They probably spend about 70-80% of their time out there in the summer/spring/fall for the sunlight, and about 50% of the time in the winter. The cats really are horribly spoiled, but I want them to be happy when I am not present.
I'd put up pics, but it would be quite doxing since it is a rather unique setup.