Any engineers or handy types willing to help me build this?

I’m sending this to Lucky Guy. (And since MIlo clearly posed for that picture, I hope you know where to send his royalty check.)

Syz: Our local Humane Society/ Animal Shelter has a large and much more serious version of this attached to the outside wall of their building. It allows all the cats (maybe as many as 15) to wander in and out at will during the nice weather.) There are mini-cubicles and many varieties of scratching posts, cat trees and cat beds and baskets.

It is pretty straightforward and made of out cyclone fencing in the form of a very large cage with the fourth wall being the exterior wall of the shelter with its windows that can be open and shut.

I bet that any competent builder could do it. Perhaps talk with the guys at the building supply store also.

I’m sure you will get a lot of help forthcoming.:-)
What about a screened porch for real fresh air and you could “decorate” it with cat furniture and large indoor plants etc.?
I think a cat porch would be awesome, especially in summer, but you would need to use stainless steel screening or mesh not nylon screening to avoid rips and tears.
If installing a cat greenhouse window costs you at least a few hundred bucks maybe you could hire a handyman or do it yourself, and for the same cost you could actually create a kitty habitat with outdoor exposure for the fresh air, sunlight and savory scents. :-)

I was initially thinking plexiglass, which would be cheap, but it would probably discolor in sunlight. I went to a search and found this company. Here’s a link.
http://www.e-bentglass.com/tempered_glass.html
They could make the sides. Don’t know about the cost. I’ll look some more.

What is the weather like in your area? Do you have to worry about snow load? Will this be in full sun – UV exposure? Do you need to worry about wind and rain.
How about trying a used fish tank that you purchase at GoodWill for a few dollars? It would be waterproof, and strong can be fit into the window like a window air conditioner.

@LuckyGuy I’m in NC, so highs in the 90’s in the summer, lows rarely below 20’s in the winter. Some direct sun, definately exposure to rain.

I thought about a fish tank; I suppose I could flip it over so the glass bottom becomes the ceiling and then create a floor. I’m stumped as to how to stabilize a glass box with no lip to a window frame, and especially to have it be aesthetically appealing.

These are mostly commercially available, meaning that they’d also come with guarantees for their intended purpose, warranties, and compliance with local building codes. Don’t forget the building codes.

@CWOTUS has the right idea but those will be expensive. I was thinking of a quick an easy solution like turning the fish tank sideways so the opening faced into the house. To hold it in place, depending upon the material, I would do something simple like drilling two holes in one edge so you could lower the window down on to it and pin it with a couple of ¼ inch wood dowels. It would be easy to remove when you wanted.

I have never seen the plexiglass ones, but I know many people who have the wire types. Some are home made and some were purchased. Seems to me it would be easy to make a wire tunnel type thing. Make it in sections and you could add to it any time you feel like building a new section. If you want to save money, source old skids or pallets and use them to make the frames and a wooden floor. they could go around your house, into trees! I always wanted to make one but always had cats who used the dog doors and I couldn’t contain them. I have a picture in my mind that looks like the hampster cages with all the tunnels etc. only made out of wood and wire. Are you getting the image???