Yesterday I was watching a home improvement show where the guy was trying to make the whole house more energy efficient. He did lots of things that I thought were neat and I took notes on this so that way I can try it later on.
One of the things they did was replace the windows with upvc sash windows. These help in saving energy for having a thicker glass that prevented heat from leaving the house as easily as the old windows did. The whole window was made so that no heat can leak out easily. I thought that was smart and started wondering how thin my glass was and if I needed to replace those as well.