I have a Four Seasons Solarium. It was built about a year before I purchased the home. It has always leaked from the ceiling windows.. When the supplier (franchise) did respond once, it looks like they shot some caulk around one of the thermal seal windows. It did not work. I travel a lot and never pursued this as actively as perhaps I should have. Fast forward about 20 years to today. All the windows in the ceiling have failed and three of the casement windows have rotted out. I'm having the entire structure torn down but keeping the brick base on brick floor. I'm then having a glorified porch ("three seasons room") built on top of the structure by a local contractor. It will be screened in with what are essentially storm window that can be raised to keep out the elements. There's no drainage on the floor so I have to keep the elements out. The roof will be shingled with the same pitch of the roof. Cost is around $15k which includes demo. The key part is that all the components that will be used will be standard items that I can find at Home Depot in case replacements are needed. No heat - I'm convinced that the baseboard heating in the winter with cycling off and on helped cause ...f the ceilings windows and their failing. My take away is that if you want a year-round room have a real addition built on your home. IMHO, forget about any pre-engineered kit. BTW a few years ago I considered having Four Seasons come out and estimate what it would take to replace it. The local franchise wanted to charge me for a service call. I decided to wait a couple of years and the take the action I mentioned above. My house backs up to woods so for the most part our subdivision neighbors were spared having to look at it. Fortunately I have understanding neighbors on either side of me. Good luck - hope this helps.
9 years of frame, leaks, seal failures, frame and run around