Windows are 6-10 times less effective at retaining internal home temperatures than an insulated wall. No amount of window improvement will make it as energy efficient as a solid, insulated wall. In most cases, improving the windows you currently have in your home makes more sense than purchasing new windows. When pursuing energy efficiency from your current windows, consider improving the sealing of your existing windows. This is likely to present the greatest return on your investment.
If new windows are a must in your home, consider investing in Energy Star windows — which are more durable and can save you signifcantly more money.
Here are some frequently asked questions about windows and energy efficiency:
What should I do if I feel a draft from my windows?
Using caulk or other weather sealing treatments may be right for you — especially if your windows are relatively new.
I already have double-pane windows, but I would like to make my windows even more efficient.
Further air sealing can help in these situations. Replacement in this instances will only yield marginal improvement in efficiency.
What should I do if I only have single-pane windows with no storm windows?
Unless you are already planning on upgrading your windows, consider purchasing quality storm windows, or sash replacements.
I can’t open my windows, are they still leaky?
The likely answer is yes. If you cannot open your windows and do not want to, further air sealing is likely to yield higher energy savings. If you want to be able to open your windows, new sash replacements or window replacements might be right for you.