A blue, insulated door on the front of a house with stone cladding. There is a bush on either side of the door.

As we become more and more aware of climate change and our impact on the environment, we are looking for ways to reduce our carbon footprint.

One way to do this is to invest in energy-efficient home products. An insulated door is one such product.

Why not download our energy efficiency E-book, which has much more information about how to save energy in your home.

An insulated door is highly energy efficient thanks to its thermally insulated core and excellent air sealing around its edges. The core is typically made from polyurethane and reinforced with vinyl, fiberglass, or steel. The airtight seal is provided by weatherstripping to prevent drafts.

In this blog post, we will explore the benefits of insulated doors and how they can help you save energy and money.

We will also discuss the different types of insulated doors available on the market and how to choose the right one for your home.

Characteristics of an Insulated Door

An insulated door, painted dark gray. The door is open showing a plant in a pot sitting on a tiled floor on the other side.
An insulated door can reduce energy bills and improve the comfort of your home.

Although there are several types of insulated doors, they share specific distinguishing characteristics that separate them from typical, non-insulated doors.

Here are some of the key identifying features of an energy-efficient door.

Construction Material

When it comes to energy efficiency, not all doors are created equal. The most energy-efficient doors are typically vinyl or fiberglass.

These materials provide the best insulation and will help keep your home cooler in the summer and warmer in the winter.

On the other hand, doors made of aluminum or steel are not as energy efficient.

These materials conduct heat, which means they will make your home hotter in the summer and colder in the winter.

If you live in a climate with extreme temperatures, it’s best to avoid these materials altogether.

Polyurethane Foam Core

A closeup of the corner of a piece of rigid foam board insulation.
Doors insulated with a foam core provide excellent thermal insulation and help to minimize energy losses.

When shopping for an energy-efficient door, you should consider a few factors.

Apolyurethane foam core is one of the essential features of an energy-efficient door. It comprises two layers of metal with a layer of foam in between.

Polyurethane foam is an excellent insulator that helps keep heat from passing through the door. It also helps to reduce noise pollution.

Polyurethane foam core doors are an excellent investment for your home or office and can help you save money on your energy bills.

For more information about insulation in the home, check out our article on the subject, here.

Magnetic Seal Strip

In addition to a polyurethane foam core, an energy-efficient door will also have an airtight seal.

This seal helps prevent air from leaking around the door where it meets the frame, preventing energy losses and lowering energy bills.

An excellent way to test for an airtight seal is to use the paper test. Put a piece of paper between the door and the frame, then close the door.

Now try to move the paper by pulling gently on it.

If the paper moves, this indicates a gap that will allow air to pass through, and the door is not tightly air sealed.

For enhanced air sealing, a well-sealed door will often have a magnetic strip that creates a tight seal when the door is closed.


The U-factor is a measure of heat transfer through a material. The lower the U-factor, the better the door keeps the heat in or out of your home.

In general, insulated doors have a U-factor of 0.35 or less. This grading reflects the door’s ability to reduce heat transfer and, thus, its ability to insulate your home or office environment. 


Energy-efficient doors must have a high R-value, which is simply the mathematical inverse of the U-factor (also known as the U-value).

The R-value measures the door’s ability to resist heat flow. The higher the R-value, the better the door keeps the heat in or out.

Many factors contribute to a door’s R-value, but the material used to construct a door is one of the most critical factors.

Solid wood doors, for example, have a higher R-value than doors made from hollow core materials.

Other factors that affect a door’s R-value include the door’s thickness, the type of sealant used, and the door’s finish.

Energy Efficiency Certification

The US Environmental Protection Agency’s (EPA) ENERGY STAR program recognizes products, including doors, designed and built to reduce energy consumption.

A door must meet strict energy efficiency criteria set by the EPA To earn the ENERGY STAR label.

Doors that have earned the ENERGY STAR label are independently verified to save energy and money and protect the environment.

Identify the ENERGY STAR label when shopping for doors to be sure you are buying a product that saves energy.

In addition to the ENERGY STAR label, some manufacturers also provide information on a door’s R-value.

Are Insulated Doors Energy Efficient?

Insulated doors are doors that have an additional layer of protection against heat or cold, making them more energy efficient than traditional doors.

According to studies, insulated doors can be up to 40% more energy efficient than non-insulated ones, allowing you to control your home’s temperature more efficiently.

If you’re looking to reduce your energy bill, adding an insulated door can help reduce the need for air conditioning and heating.

By definition, an insulated door is a door made of materials that prevent heat transfer. This quality means they are effective at keeping the heat in or out of the building, depending on your home’s needs.

There are a few things to consider when looking for an insulated door.

The first is the climate you live in—if you live in an area that gets very cold in the winter, you will want a door to keep the heat inside your home.

If you live somewhere hot like Arizona, chances are you want to keep the hot air from coming inside.

Manufacturers design doors to suit particular climates, so do your research before purchasing.

Is It Worth Installing Energy Efficient Doors?

As energy costs continue to rise, more homeowners are looking for ways to reduce their energy bills. One way to do this is to install energy-efficient doors.

In one scientific study, research suggests that windows and doors account for 20 to 30 percent of the whole heat loss of a house.

So, replacing your older wooden door might save you considerably on energy bills!

So, are energy-efficient doors worth it?

The answer depends on a few factors, including the climate and the type of doors you’re looking to install.

However, in most cases, energy-efficient doors will pay for themselves over time in the form of lower energy bills.

Benefits of Installing Energy Efficient Doors

  • You can save money on your energy bill.
  • An energy-efficient door will keep your home warmer in the winter and cooler in the summer, making it more comfortable for you and your family.
  • An energy-efficient door will also help reduce noise pollution, absorbing sound better than a non-insulated door.
  • Installing an energy-efficient door can also increase the value of your home, as it is a selling point for potential buyers.
  • They are eco-friendly and help the environment.
  • Energy efficient doors are also more durable than non-insulated doors, as they are less likely to warp or crack due to temperature changes.
  • They can help prevent unwanted air drafts.
  • Energy efficient doors that incorporate glazed panels also help to Block harmful UV Radiationfrom entering the household.

Disadvantages of Insulated Doors

  • One of the most significant disadvantages is the cost. Energy efficient doors can cost up to four times more than traditional doors. That’s a substantial investment for the average user.
  • Energy-efficient doors can be challenging to install. If you’re a novice in home improvement, you may want to hire a professional to help you with the installation.
  • It may not be as aesthetically pleasing as other options.
  • Additionally, energy-efficient doors can be challenging to find in standard sizes. This size issue means you may have to place a customized order, which can add to the overall cost.

Types of Doors and Their Energy-Efficiency Comparison

A natural wood front door with black door hardware.
Wood is a naturally good thermal insulator. However, it can’t compete with a modern insulated door with a foam insulation core.

Each door’s energy efficiency is dictated by its composite materials. Let’s discuss the various types and how they compare in efficiency.

Wooden Doors

Wooden doors are not typically very energy efficient due to the wood itself.

Wood is a decent thermal insulator thanks to the air pockets in its cellular structure. However, more heat will escape through a wooden door compared to a properly designed energy efficient door.

A typical wooden door will have an R-value ranging from R-3 to R-4.

Wood also deteriorates over time — leaving gaps that allow heat loss from your home.

However, there are ways to make a wooden door more energy efficient. For example, you could add weatherstripping or install a storm door.

Steel, Vinyl, and Fiberglass Insulated Doors

These days, doors made from steel, vinyl, and fiberglass usually incorporate insulation into their construction.

Insulated doors reduce the transfer of heat, keeping warm air inside the home during winter and cool air in during the hot summer months.

Steel offers noticeable security benefits thanks to its high strength, making it resistant to intruders.

The insulated doors’ R-values vary according to their design but typically range between R-5 and R-6.

How To Make Any Door Energy Efficient

If you have an existing door, you can opt to enhance your door’s insulation capacity. There are several ways to ensure your door is energy efficient—let’s explore these methods below!

Insulate Your Existing Door

There are several ways to insulate a door, but weatherstripping is the most common method.

This method is relatively cost-effective and reduces heat transfer in your existing door.


A door with a white edge being fitted with black rubber weatherstripping.
Weatherstripping can have a massive impact for the better on the air sealing around your doors. This will reduce energy losses and save you money.

Weatherstripping is a process in which you seal off any gaps or cracks around your door to prevent drafts.

Drafts are one of the main ways heat escapes from your home, so by sealing them off, you can help improve your home’s energy efficiency.

  1. Start by measuring your door to see how much weatherstripping you need.
  2. Cut the weatherstripping to size using a utility knife.
  3. Peel off the adhesive backing on the weatherstripping and press it into place along the top and sides of the door frame.
  4. For the bottom of the door, you can use a door sweep or brush weatherstripping.
  5. To install a door sweep, hold it up to the bottom of the door and mark where you need to cut it to size.
  6. Use a utility knife to cut the door sweep to size, peel off the adhesive backing and press it into place.

Other Methods to Insulate Your Existing Door

  • Door sweeps. Door sweeps block gaps at the bottom of your door utilizing rubber, plastic, or bristles.
  • Adding storm doors. Adding a storm door to your existing door can help prevent heat loss and drafts.

Air sealing is a crucial step to ensuring your home is energy efficient. Read our article on the subject, here.

Choose Energy-Efficient Materials

There are many ways to make a door energy efficient. The most common and effective way is to select a door that uses energy-efficient materials in its construction.

As described above, doors incorporating a thermally insulating core and high-quality weatherstripping offer the best energy efficiency.

Doors built using these materials can be found at most hardware and home improvement stores.

Ensure You Have Suitable Door Frames

When it comes to door energy efficiency, the frame plays a significant role. A door frame made of high-quality materials can help insulate the door and keep heat from escaping.

A well-insulated and airtight frame can significantly affect how well your door keeps out the cold (or the heat). A quality frame also helps to prevent drafts and moisture damage.

There are a few things to remember when choosing a frame for your door:

  • Ensure the frame is made from a material compatible with the door material.
  • Check the frame’s R-value to make sure it is well insulated.
  • Make sure you seal the frame correctly so that it is airtight.

With some research, you can find the perfect frame for your door that will help improve its energy efficiency.

Additional Tips To Prevent Heat Loss Through Exterior Doors

A door frame that has just been filled with spray foam sealant to block air gaps and provide an air seal. The can of spray foam is visible in the foreground.
Sealing around the door frame with spray foam can have a huge benefit by blocking drafts and preventing energy losses.

You can do a few things to prevent heat loss through your exterior doors, including the following.

  • Add door sweeps to the bottom of your doors to create a seal.
  • Caulk any gaps around your door frames.
  • Install storm doors for an extra layer of protection.
  • Choose doors with low U-factor and high R-value glass, which will reflect heat back into your home.
  • Make sure your doors are suitably insulated by having a professional check them out.

The Bottom Line

An insulated door is a door that manufacturers design with energy efficiency in mind.

The door typically comprises two layers of material with an inner layer of insulation. This composition helps to keep heat in during the winter and out during the summer.

There are many insulated doors on the market, but not all are created equal. Some are more energy efficient than others.

When shopping for an insulated door, look for one certified by the ENERGY STAR program.

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