I want to have a multipurpose enclosure around my backyard porch. I want an area that is a cat enclosure/greenhouse. The area will be right up against the house and will have a sloped roof.

I included a pic to show somewhat what I am thinking about for the cat enclosure part. In the summer it will be nicely aired out since the siding will just be mesh wire. I would like to have some type of track system added along the inside walls of the frame so that I can slide in clear polycarbonate panels during the winter which would be removable in the summer. I would store the panels in the garage in the summer. I would also like permanent polycarbonate roofing. I would like to have again some type of track system on the roof so that I can slide something on top of the polycarbonate roofing in the summer to provide shade instead. Please note that I am not trying to grow anything in the greenhouse. I simply want an area in which humans or pets can go out in the winter and it be warmer than outside of the enclosure and will hold potted plants that will survive the winter plus I can keep cats enclosed throughout the year when needed. I am tired of bringing potted plants indoors in the winter or using frost blankets on them to assure they make it through winter. I realize the area will not be sealed and wont be have an excellent green house effects but if I can just have the enclosed area be some 10 to 20 degrees warmer than what it really is outside in the winter I will consider this a win.

Has anyone done or seen someone do something like this? I am mostly wondering if this whole track system I envision will even work or if anyone has any suggestions/ideas. I am imagining the track system will look something like a curtain track system where the gap in the middle will be what is used to slide in a polycarbonate panel. I am imagining many different sized panels surrounding the entire thing. I am figuring the panels wont slide so nicely in place and it will take two people to inch them across.

Also I would like to know what would be the best and most cost efficient material to put on top of the polycarbonate roofing during the summer to help provide shade and keep the porch cooler. How about sheet metal? It is lightweight but I didn't know if placing sheet metal on top of polycarbonate would somehow warm up the place more than cool it down with the shade it would provide. One last note, I live in Texas where the temps don't dip that low but still some of my plants still die even in our winters if not kept indoors or covered up with frost blankets.