The windows in the main building are all single pane glass with aluminum frames. This is basically the worst type of window to have in conditioned spaces. Eventually, we plan to replace all of the windows in the building, but first we decided to replace the windows in the heated living quarters above the office. One window was replaced about a week ago, and the second we replaced today. The new windows are nothing fancy and are definitely not the very best you can buy. Standard vinyl frame windows with gas filled double pane glass. They are however, much much better than the terrible windows they replaced. It would be nice to use the very best windows, but with the sheer amount of work that needs to be done at the campground we have to try and get the most bang for the buck. Now only one more relatively small window to replace in the apartment-then many many more in the part of the building just kept above freezing in the winter.