Small Investment, Big Savings: The Advantages of Window and Door Sealing

looking out new windows

December 17, 2017


Sealing around doors and windows is a moderate-to-difficult do-it-yourself project, according to the EPA’s Energy Star program. But don’t let that deter you – the materials are inexpensive, and the results can be significant for homes with inadequate caulking and weatherstripping. Combining sealing with other improvements, such as windows, doors, and insulation can further maximize energy efficiency.

Will My Home Benefit From Sealing Around Windows and Doors?

In some situations, the need for sealing around windows and doors will be obvious – the homeowner can feel a draft or see daylight through these gaps. Even if weatherstripping is already in place, it can wear down because of heavy use. 

In other situations, the need for sealing will be less apparent. The Energy Star website suggests looking for peeling paint or discoloration around the frames of windows or doors. If dust or small pests are making their way inside the house, this could be an indicator of gaps – requiring a closer inspection. Features like decorative molding could be hiding these gaps.

If you begin to smell odors from outside while the windows and doors are closed, this could be another sign of poor sealing.

How to Find the Air Leaks in a House

A visual inspection to look for any signs of air leaks can be useful. The Department of Energy suggests performing a more in-depth DIY inspection that can help locate harder-to-see air leaks. This process can identify gaps around windows and door frames, in addition to other areas of the home.

Here are the steps for this air leak audit:

  • Wait for a cool, windy day.
  • Turn off all combustion appliances, such as gas-powered water heaters, furnaces, or driers.
  • Close all the windows and doors in the home.
  • If applicable, close the fireplace flue.
  • Turn on all the exhaust fans (these blow air out of the house; kitchens and bathrooms are usually equipped with them). If the home does not have an exhaust fan, open one window and turn on a box fan so that it is blowing air outward (from the inside to the outside).
  • Light an incense stick, and move it slowly near common draft areas: around windows and doors, in the corners of exterior walls, near closed vent outlets, and so on. 
  • If the smoke from the incense stick is sucked out or if it wavers, this is a sure sign of an air leak.
  • An alternative is to wet your hand and run it over the same leak-prone areas. Because of the dampness on your skin, you will be able to feel small drafts more easily.

A third, more expensive option is to schedule a professional whole-house energy audit. While this service costs more than the do-it-yourself inspection, a professional can also point out other energy efficiency improvements that could lead to greater savings on heating and cooling bills.

Potential Benefits of Sealing Air Leaks and Adding Insulation

A properly sealed home undoubtedly costs less to heat and cool than a drafty house. Sealing and weatherstripping around windows and doors, coupled with proper insulation can result in monthly energy savings while improving comfort and indoor air quality.

How much money can a properly-sealed home save you in the long run? It depends on several factors:

  • The current state of your windows and doors
  • Your home’s level of insulation
  • The local climate

In northern climates such as New England, the EPA and the Energy Star program estimate that annual heating and cooling costs could be reduced by 15 to 18 percent if the home is properly air-sealed and adequately insulated. The overall average yearly savings will be lower at more southern latitudes, but the annual savings on cooling costs will be greater.

In short, every home in the country could benefit from properly sealing air leaks.

What About Weatherstripping and Sealing by Itself?

Replacing windows and adding insulation are often necessary upgrades for a truly energy-efficient home, but these projects do not fall into the do-it-yourself category. So how much can you expect to save on energy bills if you went to the hardware store this weekend, bought the necessary products, and added caulk and weatherstripping around doors and windows?

Energy.gov suggests that a simple sealing project to fix air leaks could save between $83 and $166 per year on heating and cooling costs.

Are There Any Other DIY Projects to Decrease Cooling and Heating Costs?

If you need new windows but are not ready to upgrade, you could start by applying a plastic film over your windows and caulking around the frame.

Most home improvement and hardware stores sell “window insulator” film. To apply, stick the film to the window frame and then using a hair drier to eliminate any creases or wrinkles. The plastic film can save homeowners an average of $17 per year, per window, on climate control costs, according to 3M – a leading manufacturer of such products.

Window insulator film works best in northern climates because these residents rarely open their windows in the wintertime. In hotter climates, opening the windows during the summertime, after rainstorms, or at night, can help keep the house cooler without air conditioning. Window film would be impractical during the summer in these regions because it prevents windows from opening. That said, the film could be kept year-round on windows that remain shut (such as picture windows, or windows in stairways or foyers). 

When You Are Ready to do More...

Caulking and weatherstripping can provide a great investment-to-energy-savings ratio. However, without proper insulation and effective windows, the home will not be operating as efficiently as possible.

Though adding insulation and replacing windows is not as cheap and simple as applying weatherstripping, there are ways to make bigger projects affordable. One option is to apply for PACE (property assessed clean energy) financing. PACE programs are designed to help homeowners finance improvements that increase energy efficiency, such as upgrading to Energy Star certified windows or adding attic insulation.

A homeowner who participates in a PACE program can have new insulation or new windows installed for no upfront costs. The improvements are then listed as a single line item on your property taxes and paid back over time. Therefore, PACE programs make it possible to complete energy-saving upgrades, so that you can start enjoying the benefits immediately.


PACE can help you finance windows and doors, making your home more comfortable and energy efficient. Contact Ygrene at (855) 901-3999; info@ygreneworks.com to learn more.