• Skill Level: Beginner - Intermediate Help
    Time Required: Variable

    Air conditioning and heating systems use more energy than anything else in your home. In fact, the U.S. Department of Energy estimates that half of your energy use goes toward heating and cooling your home. Think about it. That's almost half your utility bill!

    The best and easiest way to cut these costs is by sealing and insulating your windows and doors. This page focuses on How to Seal and Insulate Your Windows and, depending on which solution you choose, the project will require either a beginner or intermediate level of do-it-yourself skills. But the main thing you need is a can-do attitude - and a strong desire to cut your energy bill.


    Add to My To Do List

The "How To" Video

If you want to see someone do the project first, take a minute to look at this video from the U.S. Environmental Protection Agency. It gives you a brief overview so that you can visualize it in your mind. The written directions here capture the main instructional elements of the video, and they also include some product suggestions to help you save even more money.

Before You Start

The first thing you should do is walk around your house and find which windows need to be sealed. There are several ways you can do this:

  • If it's a rainy day, check for signs of moisture along the window frame.
  • If it's a windy day, moisten the tips of your fingers, run them along the window frame, and see if you can feel the air coming through.
  • If it's a sunny day, look at those same areas around the edges of the window frame and check to see if there's any daylight coming through.
  • Or take an incense stick, light it, then hold it at various places around the frame, and see if the smoke moves - which indicates a draft.

Your Insulating Options

Once you've counted and measured the windows you plan to seal, the next step is to decide how you want to seal them. There are several ways to do this. The first three options listed below are temporary solutions that are inexpensive, easy to install, and easy to remove. The last two options are more effective and permanent solutions.

  • Window Storms
  • Window Panels
  • Rope Caulk
  • High-Performance Sealant
  • Low Expansion Foam

Window Storms

For a quick storm, inexpensive window storms are a short-term solution to reducing drafts. The storm is installed by attaching adhesive white plastic channels around the frame of the window. The clear vinyl is then spread across the face of the window and held in place with a thin plastic strip - called the spline - that locks into the channel. The plastic storm spline and channels can be cut to size with a utility knife, and the clear vinyl can be trimmed with scissors.

Window Panels

Window panels are sturdy aluminum frames that mount on the indoor side of existing windows. The weatherstripping around the perimeter of the frame seals the window, eliminating drafts and creating a thermal barrier. The frame has two separate surfaces of clear, flexible glazing material with a 7/16" pocket of air between them. When the panels are in place, a second air pocket is created between the energy panel and your existing window. They're easy to construct and all hardware is included in the kit.

Rope Caulk

If you're looking for a longer-term temporary solution that can be easily installed and easily removed, you might want to consider rope caulk. This is essentially putty in a roll, so all you have to do is put it into place with your fingers. You can also remove it with your fingers whenever you want! This makes it perfect for seasonal needs, or if you're renting an apartment and can't make permanent changes.

High-Performance Sealant

High-performance sealants are a more permanent and effective sealing solution for gaps and cracks around windows and doors. When cured, the sealant is resistant to mold and mildew and can be painted. Besides windows and door frames, it can be used to seal around sill plates, electrical and plumbing penetrations, and other areas where water and air can get in. It also works well on vinyl, aluminum and fiber cement siding, brick, concrete, metal, and most common building materials.

Low Expansion Foam

Low expansion foam is another more permanent and effective sealing solution for gaps and cracks around windows and doors. The main difference with high-performance sealant is that, since the role of low expansion foam is air sealing and not insulation, more is not always better. Just a bead of foam, enough to close the gap and stop air movement, will generally be sufficient.


Remember, according to statistics, almost half of your utility bill goes toward heating and cooling your home. So whichever sealing and insulating product you choose, whether it's a temporary solution or a more permanent one, you're taking a major step toward saving energy and saving money. So make a commitment to yourself, check over the options above, and start today!