Buyers Guide to Energy-Efficient Windows

April 13, 2023

Believe it or not, while windows only make up 8% of the average home’s exterior, they account for 45% of heat gain or loss. If you’ve ever had old, single-pane windows, then you already know how they can diffuse cold in the winter or seemingly offer no resistance to the sizzling sun in summer.

Energy-efficient windows can make such a huge difference in your home’s energy usage, your utility bills, and your own comfort. Considering investing in replacement windows? Let’s review what you need to know before you buy.

Why Choose Energy-Efficient Windows?

Windows don’t just brighten your home with natural sunlight and give you beautiful glimpses of the outdoors. They also play a huge role in your home’s overall energy efficiency. Choosing energy-efficient windows is an investment that keeps on giving.

Cost Savings

If your air conditioner and heater seem to be working overtime, your windows could be the culprit. Poorly insulated windows could be forcing you to spend more on utilities. By switching from older windows to ENERGY STAR-certified windows, you could save up to 12% on your energy bill or between $200 to $600 per year, depending on where you live. Additionally, you may be able to recoup up to 75% of your window replacement project costs through increased home equity. Not a bad deal!

Increased Comfort

Living with old windows in your home is uncomfortable. They can slowly leak cold or hot air into your home, leading to drafts, cold spots, and heat pockets. Energy-efficient windows, on the other hand, are great at maintaining a consistent indoor temperature.

Environmentally Friendly

Every time your air conditioner or heater clicks on, your home uses energy. In fact, roughly 20% of greenhouse gas emissions in the U.S. come from residential energy use. If you’re looking to lower the environmental footprint of your home, energy-efficient windows can be a big help by reducing use of your heating and cooling systems.

How Energy-Efficient Windows Work

Back in the day, all windows were made of single panes of glass and were fitted into homes with wooden frames that would inevitably warp over time. We’ve come a long way since then. Modern windows use advanced technology to stop cold and heat transfer in their tracks. Here’s a quick breakdown of the factors that impact a window’s energy-efficient capabilities:

  • Type of Frame: Vinyl frames offer great thermal performance when installed correctly and filled with insulation. Fiberglass windows also make great insulators compared to wood or aluminum.
  • Glass Panes: More than one glass pane helps to resist heat transfer and improve insulation in your home.
  • Low-E Glass Coating: Low e coating allows for optimal natural light and minimal heat/UV rays. The process is selective of the solar spectrum it lets in.
  • Warm Edge Spacer: Maximizes energy efficiency and improves seal performance of insulated glass units.
  • Weatherstripping: Weatherstripping, also known as a window gasket or window seal, is an insert in your windows to prevent outside temperatures from seeping into your home. This keeps the inside of your home cool in the summer and warm in the winter, which is how it should be.
  • Gas Fill: Argon gas is often used in multiple pane windows. This insulates the window and provides optimal comfort in your home.
  • Proper Installation: Without proper window installation from a certified team, your windows could be subject to extra costs. Improper measuring or overall fit allows air in and heating or cooling out.

Terms to Know

Before making a big investment in replacement windows, it’s important to understand some of the current terminology that will come your way as you begin your “window shopping.”An infographic labeling energy efficiency ratings.

Understanding these common terms will help you make a more informed buying decision.   

  • U-Factor Rating (Thermal Transfer): This is the rating that organizations such as Energy Star use to qualify energy-efficient windows. The U factor measures the energy efficiency of the entire window and is the most important rating to look for.  
    • What to look for: Low numbers  
  • Solar Heat Gain (Radiant Heat): Radiant heat is most easily noticed by the hot spots that one feels when he touches the floor where the sun has been shining. In northern states, a higher SHGC is better because it lets in more radiant heat. In southern states, where keeping a house cool is more important, a lower SHGC is better. 
    • What to look for: High numbers in the North, low numbers in the South 
  • Air Leakage Rating (Tightness): Air leakage ratings are represented by the tightness of your window, measuring how much air escapes. Air escaping through windows and doors can account for up to 35% of heating/cooling loss. 
    • What to look for: Low numbers 
  • Visible Transmittance (Tinting): The tint in your window is simply the amount of visible light that a window allows into the room. The higher the VT, the more light passes through the window. 
    • What to look for: High numbers 
  • Condensation Resistance (Moisture): Condensation Resistance, seen as moisture or lack of moisture, measures how well a window resists the formation of condensation on the inside surface. CR is expressed as a number between 1 and 100. 
    • What to look for: High numbers  

Look for Energy-Efficient Window Labels

The easiest way to find windows that are energy efficient is to look for windows with an ENERGY STAR and NFRC label. These two labels will help ensure you invest in top-quality windows for your home.  

ENERGY STAR

A window with an ENERGY STAR label means it has met strict energy efficiency guidelines set by the U.S. government. 

ENERGY STAR certified windows are:

  • Independently tested, certified, and verified by the National Fenestration Rating Council (NFRC).
  • Independently certified to meet strict energy efficiency guidelines set by the U.S. Environmental Protection Agency (EPA).
  • Manufactured by an ENERGY STAR partner.

NFRC 

The National Fenestration Rating Council (NFRC) rates the energy performance of windows, doors, and skylights. These ratings can be a valuable tool because they help you to compare different products on an apples-to-apples basis and make an informed choice.  

Energy Star performance Ratings Graphic

The NFRC label, such as this one, provides homeowners with the key performance metrics on any window. Want the easiest way to compare window performance? Ask to see the window’s NFRC sticker!

Understanding Tax Credits for Energy-Efficient Windows

While choosing energy-efficient windows can save you money in the long run and boost the value of your home, it can still be a big upfront investment. Fortunately, the federal government is willing to chip in for many energy-efficient home upgrades, including windows.  

The biggest money-saving opportunity comes in the form of tax credits for energy-efficient windows. The Inflation Reduction Act of 2022 offers a federal income tax credit of up to $1,200 for replacing windows and skylights (up to 30% of the project cost). You can increase that tax credit up to $3,200 total by combining your window replacement with other energy-efficient home upgrades. Just keep in mind that these tax credits will start stepping down (lowering) after 2032, so you can’t wait too long to change out your windows.  

 Depending on where you live, you may also be able to take advantage of energy-efficient windows tax credits or rebates from your state or local utility companies. A knowledgeable window contractor can help you determine which local credits and rebates you qualify for.  

Choosing ENERGY Star CERTIFIED Windows

Investing in energy-efficient windows is a great way to save money on your home’s heating and cooling bills. These windows are made to keep your home comfortable all year round. When choosing new windows, be sure to look for windows with low U-factors, high SHGCs, and tight air seals. You should also consider the type of frame, low e glass, number of glass panes, and other features that are important to you. With ENERGY STAR-certified windows, you can enjoy a more comfortable and energy-efficient home. 

West Shore Home offers a free, expert consultation to help you choose the perfect energy-efficient replacement windows for your home. Our trained, full-time remodelers will work with you to personalize your window installation and ensure that it meets your needs and budget.  

From expansive bay windows to compact awnings, all our replacement windows save energy thanks to features like ENERGY STAR. To get started, simply contact West Shore Home today. We’ll be happy to answer any questions you have and schedule a consultation at your convenience!  

FAQs

What are energy-efficient windows?

Energy-efficient windows are specially designed to limit heat and cold getting into a home. They often include multiple energy-efficient features, such as double- or triple-pane glass, low-emission coatings, insulating gas fills, and more.

How do energy-efficient windows help save on energy bills?

Energy-efficient windows help keep out heat in the summer and cold in the winter. That means a home’s heating and cooling systems don’t have to work as much. This lowers a home’s overall energy usage and utility bills. Energy-efficient windows can also help extend the life of heating and cooling systems.

Are there tax credits available for energy-efficient window installation?

Yes! Through the Inflation Reduction Act, homeowners can get a federal tax credit of up to $1,200 for replacing windows and skylights. These tax credits will be in place until 2032, at which point they will begin lowering. Some states and utilities offer their own tax credits and rebates, though these benefits will vary by location.

What is the difference between energy-efficient and regular windows?

The easiest way to tell the difference between an energy-efficient and regular window is to look for an ENERGY STAR label on the window. ENERGY STAR-certified windows have been designed to meet strict energy-efficient guidelines set by the U.S. government. They are much better at maintaining indoor temperatures and reducing energy usage than regular windows.

Where can I find energy-efficient windows?

If you are planning to replace the windows in your home, an experienced window installer can help you choose the right energy-efficient windows for your project. Typically, the contractor will provide the windows. Alternatively, you can buy energy-efficient windows at most local home improvement stores, directly from window manufacturers, or from certified ENERGY STAR partners.