Seal in Savings with Efficient Exterior Doors

Exterior doors are an easy target for efficiency improvements. You can fill space around the door jamb with caulk or expanding foam. If replacing your front door, consider an energy-efficient model.

By Miranda Boutelle

Q: I like the style of my front door, but it is drafty. Can you recommend ways to fix the drafts and make it more energy efficient? 
A: The front door of your home sets the stage for the home and is the first impression for your guests. The front door is also a good place to look for energy savings. 


Efficient exterior doors seal tightly. Limiting airflow around exterior doors may result in lower heating and cooling costs. Throughout the years, the construction of exterior doors has improved to increase their efficiency. If your door is older, it likely is not insulated. 

There are two strategies to address an inefficient front door: Purchase a new one or work with what you have.

Replace your front door

If you want to replace your front door for aesthetic purposes, make it more functional, or improve its efficiency, consider upgrading to an Energy Star–certified model. The Energy Star certification ensures that the door you buy meets efficiency criteria for your local area. It also means the National Fenestration Rating Council independently tested and verified the door.

Certification requires any windows in the door to be double or triple pane to reduce heat flow, which results in a more efficient home. While windows in doors offer aesthetics, more glass means less efficiency. Energy Star defines different efficiency criteria based on the amount of glass the door has. That means that the bigger the windows in a door, the lower the efficiency. The most efficient doors have no glass or windows. 

U-factor is the primary rating for efficiency on doors and windows. U-factor is the inverse of R-value, which is the rating used for insulation. Unlike R-value where higher is better, the lower the U-factor, the more energy efficient the door. Check the U-factor on Energy Star doors at your local hardware store or online to help you choose the most efficient door in your preferred style.

Energy Star–certified doors are made of the most efficient materials, such as fiberglass, wood cladding, or steel with polyurethane foam core. They are built to fit snugly into their frames, reducing drafts and airflow. 

When completely replacing a door and the frame, you can use expanding foam or caulk to fill the space between the door jamb and structural framing. Energy Star doors have specific installation instructions to ensure the maximum efficiency. 

Work with the one you have

If a new door isn’t in your budget, there are less expensive options to reduce air leakage and improve your home’s efficiency. 

If you see daylight around the edges of the door or underneath it, look at the weather stripping. 

Weather stripping around the door jamb can be adjusted to make a snug seal. Or it can be replaced if it’s too far gone. Apply one continuous strip along each side and make sure it meets tightly at the corners. There are many different types of weather stripping products on the market, so shop around for what’s right for you. Don’t forget the door sweep at the bottom of the door.

Adding a storm door can also help improve efficiency and is less expensive than replacing the main door. Most storm doors have options for using a screen or glass. Consider a storm door that’s easy to switch between glass and screen so you can maximize the benefits year-round. 

Open the door to energy savings by improving the efficiency of your exterior doors — without compromising the aesthetics of your home. 

Miranda Boutelle is the chief operating officer at Efficiency Services Group in Oregon, a cooperatively owned energy efficiency company. She writes on energy efficiency topics for NRECA, the national trade association representing more than 900 local electric cooperatives.

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