Energy Efficient Doors: An Open and Shut Case

Home burgundy door with wreath with two white trimed blinded windows

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When looking for ways to improve a home’s energy efficiency a few things jump out as obvious such as appliances, utility systems and windows. Those get the publicity and let’s face it; it’s probably well deserved.

Nobody wants a 30-year-old fridge chugging like a train in their kitchen or an old HVAC unit sucking their pockets clean of cash every month.

With windows, not only do you get improved curb appeal, but they can help your home’s resale value shoot upward. On top of that, come within 10 feet of aging panes of glass, and the gale force rush of air makes the need for a replacement pretty apparent.

But what about doors? For many houses, it sets the overall design tone. For others, it’s a bold color or style choice to say welcome to my home. Whatever the statement you aim to make, as the primary entry into your home, the style of a front door is valued far higher than any cost savings it may give us.

Often lost in this hunt for the perfect first impression, is how much money we are sacrificing for that initial punch of style.

If you want an all-around energy efficient home, doors should be part of that conversation. It might need to be the first thing on your list. Thankfully, you don’t need to sacrifice having a glamorous front door to ensure having one that is energy efficient.

Upgrading Your Exterior Door

upgrading your door
Image via Simpson Door Co.

Doors, and particularly exterior doors, are one of the most commonly used items in our homes. Think for a moment how often you open your windows? Unless you’re from San Diego, the answer is probably not as much as you think.

Now think about the doors on your house. How often do those find their way open? And closed? And opened again? Because of this practical use, it’s hard to appreciate the wear and tear that is occurring with each swing open and close.

Seals and weather-stripping wear out. The door itself shifts a bit too far off its alignment. The sill or jamb get scraped and scratched. What once was a tight-fitting entrance has given way to  seepage of lost air, lost energy and lost dollars.

And more often than not, we fail to notice. The door continues to operate, just as it should. Also, we expect them to have a small level of air loss merely by design. Head to a friends house and check out the front or back door.

Look at that. A little peek of light gleaming through a corner. Now you don’t feel so bad since it’s not just your door letting the outside in.  On top of that, because exterior doors are usually the most robust doors in our homes, we assume they do a well enough job to insulate the area they occupy. False.

Doors are a protective barrier, just like your walls, windows, and roof. With older, poorly insulated doors, this is a particular problem since in addition to the draft of air seeping out; they often allow a lot of heat to escape too. And don’t even ask about those ornately crafted doors that are 40 plus years old.

Upgrading your impractical, though very beautiful door has never been easier. And yes, you can probably find one that looks just as good.

Exterior Doors

As we mentioned, the way a door looks gets far more attention then how it performs. Nowadays though, how it functions is equally essential. More materials and more choice mean a greater variety, which allows you to find that perfect mix of design and efficiency.

Buying Considerations

We will take a look at the three most common types of front and exterior doors in a moment. First, though, let’s look at some factors to consider.


Initially, you need to decide what you’re looking for in your new door. If you seriously want to improve the efficiency at your homes point of entry, focus on the R-Value of each door first.

As the scale used to determine the rate of heat flow loss, the R-value will give you an idea of the doors effectiveness as an insulator. The greater the R-value, the more the protection. Most doors will have an R-value of R5 or R6.

Glass Inserts

If you want to add even more style to your front door, glass inserts are a favorite way to gain a higher end look. The option is available with all three door types we cover below but be mindful of the potential loss of efficiency with this design choice.

Glass conducts heat with relative ease, so you will want glass panels that have a thermal insulator or break between the frames; usually made of plastic or a low-emissive coating.

Higher end inserts will feature multiple glass layers that can significantly reduce the heat exchange. These will, however, run a bit more expensive.


Your exterior door’s threshold commonly takes the most abuse when compared to other components of the door. Look for ones that are adjustable to maintain a tight seal through the life of the door.

Exterior Door Types

different types of doors
Image via Salmaun

Though there are some doors in the marketplace made with other materials, fiberglass, steel, and wood are the most popular choices.

All three offer some good and some not so good aspects, with fiberglass being the best all around, steel the most cost-efficient and wood the most stylish.

If you are looking for energy efficiency, fiberglass and steel are the best options. Let’s take a closer look at each.


Common, economical, and highly efficient in both warm and cold climates, fiberglass entry doors are a wise option for most people looking to upgrade their entries.

Fiberglass doors contain a polyurethane foam core sandwiched between two molded skins. The door’s construction not only makes it efficient, but the surfaces are highly resistant to moisture, reducing concerns of warping or rotting.

The design of a fiberglass door can be made to mimic the highly desirable wood door and can be stained or painted. It does not, however, possess the same sturdy feel as wood and up close, it is not the same aesthetically.


Another popular option, steel exterior doors offer a similar construction to the fiberglass option with the same polyurethane foam insert but between steel skins.

Although they are very energy efficient, the steel door will take on more wear and tear than the other two options listed here. Scratches and dents may be prevalent over time. If installed in an extreme climate, the steel door may rust if it doesn’t receive proper care.

Unless enhanced with a glass insert (which will reduce the efficiency of the door as we stated above) steel doors tend to be at the bottom of the overall design list.


From a purely aesthetic standpoint, nothing can best a wood door. Wood doors are solid and durable. They can give the entry to your home elegance that fiberglass and steel cannot match.

Unfortunately, if you are looking for a wood door to be energy efficient, you may be disappointed, as these do not rate as high as their less natural cousins.

Moisture is your most significant concern with this type of entry door. If left untreated, even minimal amounts of rain or water can easily warp the wood.

Storm Doors

If your home has a new or recently installed insulated door, a storm door will not add to the efficiency, with any additional savings being pennies.

However, these doors can extend the life of an existing entry that may not yet be ready for replacement.

To maximize your efficiency, look for a storm door that has foam insulation in the framing (usually in steel constructed models) with low-emissive glass.

Sliding Glass Doors

Most commonly used to access patios or balconies, sliding glass doors are widespread in homes across the country. They also tend to lose a ton of heat due to mainly being sheets of glass.

As with the glass inserts and storm doors, a low-emissive coating is a crucial element to look for along with a thermal break in between panels.

Again, pricier options will have multiple layers of glass panels. Depending on your long-term needs, these may ultimately be the best option if you’re looking for the most energy reduction in a door type that usually offers very little.

Installing Your New Door

Installing your exterior door
Image via DIY Network

The most significant key to installing you’re new, highly efficient door, is ensuring a tight fit. Doors will either come as a slab or pre-hung. They’re a few minor exceptions, but when replacing an exterior door, the latter is the way to go.

Slab doors come with no hardware or hinges and may often require a seasoned professional to get the install right the first time. Additionally, because of the minor tweaks that could be necessary to get the door to fit, some of the sealant qualities could be lost if not done correctly. Per unit cost, however, is typically cheaper.

Conversely, a pre-hung door is the complete package. The door is already hanging nicely in a frame with hinges. This door is the best option for entries after removal of the original structure due to damage or remodeling. Due to this, it will also maintain is efficiency seals much better.

For sliding glass and storm doors, it’s often best to contact a professional installer. If you do go the do-it-yourself route, make sure you have some extra help, especially if you have a larger space to cover with your sliding glass door.


Exterior doors serve as the gateway to our homes. While it is easy to appreciate what they provide in giving our guests a warm welcome, we shouldn’t overlook the utility dollars they are potentially taking away.

With a little insight and some smart shopping, you can easily purchase and install a door that is efficient and stylish. In doing so, you may very well welcome something else into your home—savings.

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