The house we're in has many windows that let in a lot of light, which is great. The problem is that they're drafty, single-pane windows. With winter weather on the way, I began looking for a way to improve the efficiency of the home's insulation.
Energy loss through windows can account for up to 25% of a home's heating bill.
If you want to insulate an old window you have a couple choices. If you're a homeowner with some money, you should probably consider upgrading your windows. In the long run, you'll recoup the costs and the results will look and feel a lot better than what I'm about to describe.
The other options involve using plastic to insulate your windows.
You can use double-sided tape around your entire window. Once that's in place, push a sheet of plastic wrap over the window and attach it to the tape. It should cover the glass as well as the window frame. Use a blow dryer to tighten the wrap. Watch a video of someone doing this.
There's also bubble wrap. This approach is cleaner and requires you to cut bubble wrap sheets to fit over your glass panes. Mist the glass with water and then press the bubble side of the wrap against the window. It'll stick.
According to some, you could see a 45% reduction in heat loss (his test was on double-paned windows).
The bubble wrap looks pretty good with light behind it. It's easy to apply and can be taken down easily.
Not sure yet. The bubble wrap just covers the glass, so there's still heat loss around the window frame. Still, the air around the glass is much warmer on the windows I covered. The window above the head of our bed is large and you can normally feel a cold draft. That seems to be greatly reduced now.
Bubble wrap is cheap. Take some measurements of your windows and find a roll that will work well. You can probably cover your house (or your coldest windows) with a single roll, $20 max.