Man replacing windows.

The Best Energy-Efficient Windows Guide: Fixing Or Replacing

Hanna Kielar9-minute read
August 15, 2022

Are you wondering how you can make your windows more energy-efficient and save money on your utility bills?

It all comes down to heat transfer. In the winter, the outside air naturally absorbs some of the heat from inside your home in an attempt to equalize the two temperatures. This balancing act causes the now cooler air to become heavier and then sink to the ground, bringing warmer air in contact with the windows.

The exact same thing happens in reverse during the summer, with the air inside your home absorbing the heat from outside. These fluctuations make your furnace or air conditioner work harder to cool or heat the house and potentially waste valuable energy.

To help limit this vicious cycle and allow you to start saving some money, here’s some information about windows and how to ensure they’re as energy-efficient as possible.

What Are Energy-Efficient Windows?

Energy-efficient windows, also known as energy-saving windows, prevent cool or heated air from escaping your house and reduce your home’s energy usage. This allows you to maintain a more energy-efficient home that stays cooler in the summer and warmer in the winter, all while reducing your monthly home heating and cooling bills.

What Makes A Window Energy-Efficient?

Energy-efficient windows accomplish this in a number of ways. The type of glass, type of frame and the way they are installed are just a few of the ways a window can go from energy-wasting to energy-saving.

Energy-Efficient Frames

Although there are a number of different framing options for windows and skylights, not all of them were designed with your budget and energy efficiency in mind. The main consideration here is insulation. Frames that are labeled “energy-efficient” are more likely to be well-insulated, meaning they keep the heat or cool air you want in your home from escaping. The type of material used to make the frame plays a big part in the energy efficiency of the window as well (more on that later).

Energy-Saving Glass

In the world of windows, the glass portion is called glazing. Traditionally, windows only featured one pane of untreated glass, which did little to insulate the home. However, today’s windows boast a variety of energy-saving options that you can take advantage of, including increasing the number of panes.

Proper Window Installation

Proper window installation is an important part of making a window energy-efficient, and measurements must be perfect to ensure there are no gaps.

When removing the old window, the surrounding wood needs to be checked for rot or mold. A good installer will diligently inspect the opening to make sure everything surrounding the window is in good condition.

Next, the securing and insulating of the window needs to be done in a way that leaves no gaps for heat or cool air to escape the home. This means ensuring the window is level and then caulking with attention to detail.

Need extra cash for home improvement?

Use your home equity for a cash-out refinance.

NMLS #3030

How To Make Existing Windows More Energy-Efficient Without Replacing Them

If replacing all your windows is cost-prohibitive, there are a number of other ways you can make them more energy-efficient. Here are just a few of the many tactics you can employ.

1. Install Window Film To The Glass

Installing window film will help you make your glass windows more energy-efficient. Window film can be purchased as either a kit or in a sheet, and it works just like a giant sticker that you either attach to the glazing of your windows or over the entire window frame. This film acts as another barrier to cold drafts that can seep in through poorly attached windows. It also allows for heat gain, the process by which your window absorbs heat from the sun.

2. Cover Gaps With Weather Tape

Locating window gaps and correcting them is a great way to save energy costs and keep your home at the temperature that suits you. The U.S. Department of Energy recommends doing a visual inspection to find these by carefully looking for areas where there is light around the window frame.

A great solution if you’re looking to stop hot air, cold air or rain from seeping into your house during the summer months, weather tape is specialty tape designed to cover gaps between your windows and your frames where sealant or other issues have caused the seal to weaken. This is great for the rooms where you want to maximize sunlight or just don’t want to cover the windows with anything.

3. Use Window Coverings and Treatments

Window treatments and coverings like drapes and blinds can also help to make your windows more energy-efficient. Blinds and drapes can be opened and closed depending on the light you want to come in at any certain time, and they go a long way in preventing drafts that bring cold air into your home in the winter and let warm air inside in the summer.

4. Buy Plastic Sheets And Tapes

For the least expensive method of winterizing your windows, buy some painter’s tape and some plastic sheets that you would normally use to cover floors and furniture when painting. Use the tape to secure the plastic sheet around the window area. Granted, it’s not the most fashionable idea on the list, but it gets the job done and is affordable.

5. Hang Interior And Exterior Shutters

Shutters are a firm window covering made out of a series of slats that fold open and closed. They can also be swung to the side to completely reveal the window, depending on your mood or need.

Many people decide to install interior shutters rather than exterior ones, to prevent drafts and for easier access when opening and closing them. Interior shutters do need a relatively wide area of space around them to fully open and close, making them a bit cumbersome at times.

6. Install Awnings

These work as mini roofs and are installed on your home's exterior to shade your windows from the sun's heat. This can significantly reduce solar heat gain in the summer months.  

7. Add Storm Windows

Storm windows are designed to sit right outside or inside the primary window. By reducing airflow and creating another barrier between the inside of your home and the elements, storm windows can greatly increase the efficiency of your home.

8. Be Sure To Have Flush Tracks

Making sure your window tracks are intact will also help make the windows more energy-efficient. Loose or unaligned window tracks can enable airflow, but having flush tracks will prevent airflow and lessen the chance of heat escaping.

9. Replace Or Upgrade Window Frames

Upgrading your window frames is another good idea because new or improved window frames will leak less air, making them more energy-efficient.

10. Install Window Inserts

Window inserts refer to a strip of metal or wood that separates and holds the panes of a window. When installed, they create a dead air pocket between the insert and the window, resulting in less radiant energy loss. This is the same concept that makes double and triple-pane windows energy-efficient.

How To Choose The Best Energy-Efficient Windows For Your Home

If you do go the new window route, there are a few features to consider. Review the following to see how to choose the right energy-efficient windows for your home.

Energy Ratings

To help make choosing the right windows easier, the National Fenestration Rating Council (NFRC) has created an energy performance label. Companies that choose to participate are tested and certified by an independent company on a number of important factors. Reading NFRC ratings can be tricky at first, but there is a label guide available you can consult while shopping.


Metal frames conduct heat, meaning they can carry warmth to colder areas of the home, so they will bring hot air in during the summer months and take the heat out during the winter.

Wood frames are great insulators, but they require more upkeep and aren’t always the best in humid and wet environments. Remember, a mixture of wood and water can result in rot and even mold.

Synthetic frame materials like vinyl or fiberglass provide excellent insulation and durability but have some limitations when it comes to how they look. Fiberglass is the more versatile of the two, but they’re typically more expensive than vinyl windows, so choosing between them will require some consideration.

Number Of Panes

As previously mentioned, increasing the number of window panes you have is a great way to increase energy efficiency. The most common variety is double-hung glazing, which features two pieces of glass with an empty space between them. Krypton or argon gas is then pumped into this space to further cut down on temperature transfer.

Triple-pane glass takes this a step further by having a single pane of glass sandwiched between the two outside pieces. This creates two empty spaces inside the frame where more insulating gas fills the area. Because of the extra glass, this type of glazing is usually the heaviest and most expensive, but it’s also the most energy-efficient and resistant to condensation.

Window Placement And Glass Coatings

The window panes themselves can also be altered to ensure better energy efficiency. A low-emissivity (Low-E) coating can be added to cut down on the amount of infrared and ultraviolet (UV) light that’s allowed to pass through the glass.

This coating acts as another type of heat barrier, keeping it in during the colder months and out during the warmer ones. It’s also very thin and invisible to the naked eye. However, since it’s designed to block UV rays, in the winter, you won’t get the same heating benefits from the sun as you did before, so make sure to factor that into your decision.

In warmer climates, tinted glass is another great option. Specialty colors, like gray or bronze, are worked into the glass to help block solar radiation and keep the overall temperature down. Because the windows have this coloring, they will let in a reduced level of natural sunlight.

Deciding to use these windows will involve learning which side of your home gets the most sunlight, considering the climate you live in and determining whether you can live with the aesthetics of this option.

Need extra cash for home improvement?

Use your home equity for a cash-out refinance.

NMLS #3030

What Are The Different Types Of Energy-Efficient Windows?

Let’s look at a few of the different types of windows that are energy-efficient so you will be well-informed when it comes time to choose:

  • Fixed windows: This refers to windows that cannot be opened or closed. This can help reduce drafts, as they won't be left partially open accidentally.
  • Hinged windows: These windows open and close with a hinge and can have a much tighter seal than sliding windows, which helps their energy efficiency.
  • Insulated windows: This refers to windows with two or more panes of glass. The more panes, the more heat and coolness trapping occurs.
  • Low-E glass windows: When a Low-E coating is applied to windows, it helps block infrared light from penetrating the glass from the outside. This greatly increases their energy efficiency.

How To Save Money On Energy-Efficient Windows

Of course, the best way to have more energy-efficient windows is to replace any old or leaking ones. However, this can be pricey, especially if you’re set on buying triple-pane windows. Thankfully, you could use your equity with a cash-out refinance or home improvement loan.

You can also use the following tips to reduce your replacement costs and increase your energy efficiency for less money.

Find An Energy Star Seal

The Energy Star seal is the best way to ensure you are buying windows that will help you save on energy bills. Energy Star certified windows are double or triple-paned and have been tested, certified and verified by the NFRC. These are the most energy-efficient windows you can buy as they meet specific standards set by the U.S. Department of Energy.

Choose A Replacement Window With A Low U-Factor Or SHGC

The NFRC label on a replacement window will show two important types of ratings: the U-Factor and the Solar Heat Gain Coefficient (SHGC). U-Factor refers to the measure of heat gained or lost through the window’s glass. The lower the U-Factor, the better the insulating properties of the window and the more energy saved.

The SHGC is the amount of solar energy that enters the home as heat. The lower this rating is, the less heat the window will let in.

Energy-Efficient Window FAQs

The most common questions homeowners ask about energy-efficient windows are “how helpful are they”? and “how much will they help me save”? Here, we will provide answers to both of these questions.

How beneficial are energy-efficient windows?

Keeping your home warm in the winter isn't just a comfort concern, but a safety concern as well. When your HVAC system needs to work extra hard because your windows are releasing heat, it can stop working properly. That’s no joke in the cold of winter.

In the summer, your air conditioner can work overtime to maintain a steady indoor temperature as it tries to battle with windows that are letting all the cool air out. In climates with temperatures so high they’re barely habitable, this can mean potentially dangerous heat exhaustion for you and your family.

Energy-efficient windows can go a long way toward ensuring that you are safe and comfortable in your home, no matter the time of year or temperature outside.

How much can you save with energy-efficient windows?

Even though energy-efficient replacements cost anywhere from $800 to $1,200 per window, they can still be worth the investment. According to the U.S. Department of Energy, Energy Star rated windows can save you about $71 to $501 per year. Depending on where you live, your savings could be even more significant.

The Bottom Line: Energy-Efficient Windows Could Help Lower Your Electric Bill

Using energy-efficient windows can really help you save on costs. In addition, using less energy is always good for the environment, so you can feel good about doing your part to save the planet too.

If you’re looking at options to finance your window upgrade, a cash-out refinance can be a great option. Cash-out refinances let you leverage existing equity for cash that you can reinvest back into your home in the form of value-enhancing and cost-saving renovations. If that sounds like it will work for you, why not start the process to get a cash-out-refinance today?

Need extra cash for home improvement?

Use your home equity for a cash-out refinance.

NMLS #3030

Hanna Kielar

Hanna Kielar is a Section Editor for Rocket Auto℠, RocketHQ℠, and Rocket Loans® with a focus on personal finance, automotive, and personal loans. She has a B.A. in Professional Writing from Michigan State University.