After a short holiday break (and because it was too cold to work!), we installed the windows in February. These are Anderson brand double-pane argon-filled casement windows. Update 2022. Insulation factor. These windows are fantastic. It can be -10F outside and putting your hand on the glass inside the house, you can’t even feel the cold. I have never put curtains over them because I love the pretty snow forest outside and the home stays nice and warm.
