Purchasing energy-efficient windows and doors for your home will aid in reducing your energy bill and increasing the comfort of your home. While you may have already decided to buy energy-efficient windows and doors, you still have to decide which ones are best for your home.

With any window or door choice, there are several options available regarding style, materials, and features specific to your climate. Knowing about the various choices available to you will help you make an informed decision on the best energy-efficient windows and doors for your home.

Our Companies Are Backed by the Best Pick Guarantee. Call One Today!

Types of Energy-Efficient Windows

professional window installer

As you get ready to buy energy-efficient windows, you’ll need to carefully consider the three components that contribute to a window’s energy efficiency: the frame, the glass, and the window’s operation.


The frame is the material that surrounds and supports the glass. Window frames are available in several different materials, such as wood, aluminum, or vinyl, and each material offers different energy- and money-saving properties. Take a look at the chart below to learn more about the advantages and disadvantages of each material.

Frame Material Advantages Disadvantages
Aluminum/Metal Low maintenance; strong; lightweight material Conductor of heat
Composite Strong; resistant to warping, fading, and denting; insulates as well as wood May cost more than other options
Fiberglass Provides better insulation than wood or vinyl frames May cost more than other options
Vinyl Great against moisture retention; widely available Cannot be painted if you want a different look
Wood Offers great insulation; available in many styles Requires more maintenance than other materials; must be clad with metal or vinyl to improve ease of care


Window glass comes in an array of types for the efficiency-minded homeowner. As a general rule, windows with more than one pane of glass will provide more insulation for your home.

Single-pane glass is common in older homes and is not recommended for replacement windows. The main problem with single-pane windows is that one sheet of glass provides very little insulation against heat, cold, and noise.

Double-pane glass is perhaps the most popular option in replacement windows, and it’s the industry standard in new construction. Double-pane windows insulate your home with the help of argon or krypton gas between the sheets of glass. Your home will be quieter and more comfortable with double-pane windows, and you’ll see a reduction in your heating and cooling costs.

Triple-pane glass is less common than double-pane glass, but it’s a great option if you live in a part of the country that experiences extremely cold winters. If you live in a more temperate climate, think carefully about whether triple-pane windows are the best choice—recouping your investment may take a long time.

Additional options such as energy-efficient coatings and after-market tints provide even more insulating properties to the glass in your windows.

Low-emissivity glass (or low-E glass, in industry terms) is window glass that has been manufactured with an energy-efficient coating. This microscopically thin glaze blocks UV and infrared rays from the sun but doesn’t make a noticeable impact on the amount of sunlight that enters a room.

A low-E coating cannot be applied after a window is installed, so if this is a feature you’re interested in, be sure to ask your window and door replacement company about it before you make any purchase decisions.

Solar control window film filters UV rays and can be applied after a window is installed. Some window films are reflective, while others have a less noticeable effect on the window’s appearance. Talk to a qualified installer to find the best option for your home.


How your windows operate also contributes to their energy efficiency. If that comes as a surprise to you, think about it this way: A window’s energy efficiency is largely related to how much air escapes through the glass and around the frame. Even with tight seals and gaskets, a window that opens will always release more air than one that does not.

Awning, casement, and hopper-style windows permit less air leakage than single- or double-hung windows. Fixed windows have an airtight seal, but they cannot be opened for ventilation.

Types of Energy-Efficient Doors

burgundy entry door

Entry doors

Your home’s front door is an important aesthetic choice as well as a practical feature. Fortunately, the materials on today’s market combined with advancements in manufacturing technology mean that you’ll likely be able to find exactly what you want without sacrificing your personal style.

Wood exterior doors are beautiful, but from an efficiency standpoint, they provide less insulation than steel and fiberglass doors with foam cores. If you have your heart set on the look of wood, however, you’ll be pleasantly surprised to find that some manufacturers make fiberglass front doors that are virtually indistinguishable from their solid-wood counterparts.

Patio doors

Patio doors are traditionally glass to keep the view to the outdoors nice and open, so by default, they are less energy efficient than entry doors. But that doesn’t mean that energy-efficient patio doors don’t exist! The best energy-efficient patio doors will share many of the qualities of a good, energy-efficient window:

  • Two panes of glass, with insulating argon or krypton gas between them
  • Fiberglass, vinyl, or wood frame
  • Installation by an experienced professional to ensure a tight fit

Sliding glass doors offer better energy efficiency than French doors, but you’ll need to keep a close eye on the seals, especially if the door receives a lot of use. The friction from sliding the door open and closed can cause the seals to wear down over the years, which decreases the door’s efficiency.

Energy-efficient French doors are available, of course, but the fact that both panels open (as opposed to just one in a sliding door) means that their efficiency rating will be slightly lower than that of a sliding patio door. Replace any failing seals on your French doors promptly to reduce air leaks.

How to Read an ENERGY STAR Label

energy star label

When you buy new windows and doors, keep an eye out for options that carry the ENERGY STAR label. These products are known to reduce energy costs by 12 percent, on average, over their traditional counterparts.

ENERGY STAR is a government program responsible for identifying energy-efficient products available for consumers, and its label ensures that the windows and doors you are buying are truly energy efficient.

When you look at an ENERGY STAR label on a window or door, you’ll see measurements from the National Fenestration Rating Council (NFRC). If those numbers look like gibberish to you at first glance, you’re not alone!

Here’s a quick guide to the terminology you’ll need to know:


The U-factor measures how well a window or door insulates your house. U-factor numbers range from 0.25 to 1.25, and a lower number indicates that a product provides better insulation.

Low-E glass lowers a window’s U-factor, as do multiple glass panes and the addition of an insulating gas between the panes. Take U-factor measurements into account regardless of where you live, but having windows and doors with a low U-factor is especially important if you live in a cold climate.

Solar Heat Gain Coefficient (SHGC)

The Solar Heat Gain Coefficient (SHGC) measures how well a window or door blocks the heat from sunlight. SHGC ranges from 0 to 1, but you will typically find numbers between 0.25 and 0.80.

Normally, when looking for the best SHGC, the lower numbers are better; however, if you live in a colder climate, look for a higher SHGC rating. A higher SHGC means the product is better at collecting solar heat and contributing that heat to your home. For warmer climates, a lower SHGC means the window or door is better for blocking heat gain and keeping your house cooler.

Visible Transmittance (VT)

While the U-factor and SHGC measure how heat interacts with the glazing on your windows, visible transmittance measures the amount of light that comes through your windows. When you add more glazing to your windows, the VT decreases.

VT is measured on a scale of 0 to 1, and you will typically see values from 0.20 to 0.80. If the VT drops below 0.40, everything you see through the window may appear gray. If you want a lot of sunshine to come through your windows, choose a window with a higher VT rating, but consider your options wiselysinceunfiltered sunshinecan fade furniture, carpet, and flooring.

Air Leakage (AL)

The air leakage rating measures how quickly air escapes through joints or cracks in a window or door. A lower AL number equals less air leakage.

The standard value is 0.3 cfm/ft². The air leakage rating is important because openings in windows and doors can allow moisture to enter your home and createmold, which could lead to health issues. Moreover, properly sealed windows and doors can save you money on heating and cooling bills by better preserving your home’s interior temperature.

Condensation Resistance

Condensation resistance is a measurement of how well a window resists moisture buildup. This feature is measured on a scale of 0 to 100, with a higher numbercorresponding to windows with a high resistance to buildup, especially in wet or humid climates.

Proper Window and Door Installation

carpenter installing window

The best energy-efficient windows and doors are only as good as their installation, so select your installation company very carefully. Best Pick window and door companies carry general liability insurance as well as state-required workers’ compensation insurance and licenses, and they must meet our high standards for quality of work, cleanliness, and customer service. When you hire a Best Pick, we guarantee that you’ll be pleased with the experience and the end result.

Didn’t use a Best Pick? Keep an eye out for the following signs of a less-than-stellar window or door installation:

  • A door that doesn’t hang level in the frame
  • Windows or doors that require significant force to open or close
  • A door that creaks loudly and consistently
  • An increase in your heating and cooling costs

Improper installation can shorten the lifespan of your new doors and windows and make them less efficient. Also keep in mind that an installer who does not follow the manufacturer’s installation procedure will void any manufacturer warranties on your windows or doors—not something any homeowner wants.

The Bottom Line

Efficient windows and doors are essential to a house that is comfortable to live in and that doesn’t break the bank every month. There are many products to choose from on today’s market, and while that can be overwhelming at first, a window and door replacement expert can help narrow your options.

  • Carefully consider your climate, your budget, and the approximate market value of your home to settle on the best products for you.
  • Opt for ENERGY STAR windows and doors when they’re available.
  • Be sure to carefully read the attached label with NFRC ratings—that information will give you an apples-to-apples comparison of each product’s efficiency features.

Once your new energy-efficient windows and doors are installed, all you’ll need to do is enjoy the improvement in your energy bill and the look and feel of your home.