Weatherization, Windows & Insulation

Save energy and improve comfort throughout the year

Insulation supplies

You don't have to be a whiz at home improvement to take advantage of these money-saving weatherization tips. Most local building supply stores stock a variety of insulation, caulking and weatherstripping products. Just a few hours of time can add up to big energy savings and increased comfort. To learn more, click on a section below; click on it again to "close" it.


Because heating and cooling costs make up a large percentage of your energy bill, insulating is one of the first and most practical things you can do to maximize your home's efficiency. Besides reducing energy waste, proper insulation increases comfort levels by reducing drafts and keeping temperatures more constant throughout your home. The most important areas to insulate are the attic, floors and walls.

Here's what you need to know to get the job done:

  • Determine the level of existing insulation. If there is less than 10-12 inches of insulation in the attic, more should be added. If none exists in the floors or walls (as is often the case in older homes), insulation is recommended.
  • Decide whether you want to do the insulation work or hire a contractor. Take into consideration that some insulation jobs are easier than others.
  • If you do the job yourself, follow installation instructions carefully and adhere to proper safety precautions.
  • If you'd like a contractor to do the work, make sure you get several bids. Only hire licensed, bonded contractors.
  • Decide what type of insulation you need (this will depend on the area you are insulating).

When purchasing insulation, check the R-value. This indicates the effectiveness of insulation. The higher the number, the higher the insulating capability. Ask a knowledgeable salesperson to help determine the R-value of the insulation.

Cash incentives
You may be eligible for cash incentives for insulation. Check programs for your state »

Energy-efficient windows

A home's heat loss also occurs through windows. You could reduce energy loss and improve comfort by replacing your windows if they have any of the following problems:

  • Cracked glass panes
  • Damaged window frames or seals
  • Rotten wood
  • Missing putty
  • Poor-fitting sashes

Windows are rated by a U-value, which indicates the window's insulating ability. The lower the number, the better the window is at preventing the transmission of heat. The U-value of a window is based on the number of glass panes, the thickness of air space between the panes and the type of window frame.

Storm windows & kits
Storm windows can improve the efficiency of existing single-pane windows, but they aren't as effective as new windows, which meet current code standards.

For a temporary and quick fix before the winter hits, you can purchase storm window kits. They consist of plastic film that you tape to the inside of your windows. The kits are available at most hardware stores for $3 to $8 per window and usually last between one and three years.

Window coverings
You also can reduce heat loss through windows by installing insulated curtains or drapes. They help keep heat in during the winter and out during the summer.

Cash incentives
You may be eligible for cash incentives for installing new energy-efficient windows. Check programs for your state »

Caulking and weatherstripping

In addition to inadequate insulation, air leaks are among the largest sources of energy loss in homes. It pays to seal leaks with caulking and weatherstripping materials.

Check for air leaks by using a damp hand to detect air movement. Close all doors, windows and fireplace flues and turn off all ventilating fans to make the air leaks easier to locate. The most common places leaks occur are:

  • Around doors and windows
  • Along sill plates and band joists at the tops of foundation walls
  • Behind electric outlets and switches – especially on exterior walls
  • Around plumbing pipes located in floors and ceilings
  • Around recessed lighting and ceiling fans
  • Along attic access hatches
  • Along chimney penetrations through insulated ceilings and exterior walls

The best way to fix an air leak depends on its size and location. Make sure you choose your sealants carefully. Read on to find out about the available types of sealants and how to pick the right materials to fit your needs.

CaulkingCaulk is most effective on gaps less than 1/4-inch wide. Look for caulks that will remain flexible over a 20-year period. If it will be visible, choose a tinted caulk or one that can be painted.

Expanding foam sealant
If there are large cracks and holes shielded from sunlight and moisture, try expanding foam sealant to fill them. Remember to buy only products listed as "ozone-safe."

Backer rod or crack filler
Backer rod, or crack filler, is a flexible foam material sold in long coils, with a variety of diameters available. It can be used to seal large cracks or provide backing in deep cracks to be sealed with standard caulking.

Spring metal, rolled vinyl or adhesive-backed weatherstripping may be needed depending on the types of windows and doors you have.

Weatherstripping can be purchased by the foot or in kit form. There is a special kind for double doors, which are often hung with a substantial gap where they meet so the doors can swing freely. For the bottom of a door you may want to use a "door sweep."

More energy-saving tips: