In Florida, windows are an enormous part of your home’s energy efficiency. Adding ENERGY STAR windows to your home can help you save money each month by reducing the amount of energy you need to use to cool your home.
What is ENERGY STAR? How does it work and why should you care about it? Let’s go over the basics of the ENERGY STAR program and what it means for your home’s windows (and doors, too).
What Is ENERGY STAR?
In ENERGY STAR’s own words, it is “the government-backed symbol for energy efficiency. The blue ENERGY STAR label provides simple, credible, and unbiased information that consumers and businesses rely on to make well-informed decisions.”
It’s a program that’s administered by the U.S. Environmental Protection Agency (EPA) that helps to promote greater energy efficiency to reduce pollution and waste while helping American families and businesses save money by reducing their monthly electricity costs.
How ENERGY STAR Works
ENERGY STAR is an optional program. It is not a compulsory standard that businesses have to comply with. However, many companies choose to submit their products to ENERGY STAR certification programs to earn the blue label that marks their products as being energy efficient and environmentally friendly for consumers.
In the window and door manufacturing industry, the certification program for ENERGY STAR is largely managed by the National Fenestration Rating Council (NFRC). The NFRC provides objective ratings as a third-party organization detailing the energy performance characteristics of window and door products. Odds are that you’ve seen an NFRC rating label if you’ve looked at windows in a showroom of some kind.
On the NFRC label, you can find Energy Performance Ratings detailing the window’s U-Factor, Solar Heat Gain Coefficient (SHGC), and air leakage ratings. To meet ENERGY STAR certification, a window must meet certain criteria for each of these energy performance metrics.
What Makes for an ENERGY STAR Window?
To be certified as an ENERGY STAR window, a window must possess certain U-factor, SHGC, and air leakage characteristics. However, the U-factor and SHGC requirements may vary depending on the “Climate Zone” the window is being installed in.
What Is a Climate Zone?
A Climate Zone is a region defined by the ENERGY STAR program based on the general weather characteristics of the zone. The ENERGY STAR Climate Zone Map divides the USA into four climate zones: Northern, North-Central, South-Central, and Southern.
A window that might be able to earn ENERGY STAR blue label certification in a Northern climate zone may not be able to qualify for it in a southern zone, and vice versa. That’s why it’s important to check that the window is certified for your specific climate zone.
For example, the entire state of Florida is in the Southern climate zone.
What Are the Energy Efficiency Requirements for ENERGY STAR in Florida?
To qualify for ENERGY STAR’s blue label in Florida, a window must have a U-Factor equal to or less than 0.32 and an SHGC of 0.23 or less.
However, ENERGY STAR also has a “Most Efficient Criteria” for windows that have a U-Factor of 0.21 or less and an SHGC of 0.21 or less. This is the criteria for a product to qualify for tax rebates.
This is in addition to the 0.3 ctm/ft2 (cubic feet per minute per square foot) or lower air leakage requirement for ENERGY STAR windows in general. Doors have a different standard, allowing for a 0.5 cfm/ft2 air leakage limit.
Common Features of ENERGY STAR Certified Windows
While not all ENERGY STAR windows will have every energy efficiency innovation, some common features of windows that have the ENERGY STAR logo include:
- Low-E Glass. Low emissivity, or ‘Low E,’ glass is glass that has been specially coated to enhance its SHGC value. In Florida, ‘Solar Control’ low e glass is used to reflect away ultraviolet and infrared radiation from the sun that causes your home to heat up. This helps keep your home cooler so your AC doesn’t have to work as hard.
- Double- or Triple-Paned Glass. More layers of glass between your home and the outside helps provide better insulation for your home. This is especially true when the glass layers have…
- Air Gaps. Space between glass layers act as a thermal break that limits the transfer of heat from one layer of glass to the next, which helps to improve the overall insulation of the window.
- Argon Gas Fills. Using argon and other inert gases in the air gaps between glass layers helps to further improve the thermal performance of the window for greater energy efficiency. Windows with argon gas fills use butyl or other materials to seal the gaps around the glass pane to prevent the gas from leaking out of the window.
- Vinyl or Wood Frames. Energy-efficient windows typically use frames made out of vinyl or wood because these materials have an incredibly low thermal conductivity compared to metal window frames. For example, Fraunhofer IRB notes that vinyl has a thermal conductivity of 0.17 W/m*K (Watts per meter Kelvin) while aluminum has a thermal conductivity of 160 W/m*K. In other words, vinyl transfers roughly a tenth of a percent (0.10625%) of the heat aluminum does.
Can ENERGY STAR Windows Qualify for Tax Credits?
Yes! As mentioned in the Energy Efficiency Requirements section, an ENERGY STAR window can qualify for tax incentives… if it meets the “Most Energy Efficient” criteria.
How can you check to see if a window is certified as being Most Energy Efficient? By going to the NFRC’s Certified Product Directory search page and looking for your window on it. Every NFRC-rated window should have a Certified Product Directory (CPD) number on its NFRC label. This label can be a sticker on a newly-installed window or you might have to look for a permanent etching on your window frame to find it if the sticker has been removed.
Using the CPD number, you can search the NFRC database for your window. Then, check to see if the window product is highlighted in green for your climate zone in the database. If it is, it should qualify for a tax credit from the federal government.
How Much Is the Energy Efficiency Tax Credit Worth?
In 2025, the Federal Income Tax credit is worth up to $3,200. This credit is available until the end of the year to all Americans across the country. The value of this tax credit and its availability may be subject to change in the future.
Additionally, local energy companies may offer additional rebates and incentives for installing energy efficient upgrades in your home.
What Are the Benefits of ENERGY STAR Windows?
Okay, so what’s the benefit of installing an ENERGY STAR window? The biggest benefit of making the switch to a more energy efficient window is that it helps you save money on your electricity bill every month. Other financial benefits include potential qualifying for energy efficient home tax incentives and rebates from other municipal and energy company incentive programs.
Additionally, in Florida, making energy efficiency upgrades like installing ENERGY STAR certified windows and doors can help you make your home more comfortable year-round. By blocking out the heat, your home remains cooler and more comfortable for you and your family. It also prevents drafts and the transfer of moisture from the outside, since windows have to minimize air leakage to become ENERGY STAR certified.
Where Can I Get an ENERGY STAR Window?
Okay, so, where should you go to get an ENERGY STAR window for your home? When shopping for certified energy-efficient fenestration, it’s important to go to an expert who knows the installation process and how to make the most of your new energy efficiency upgrade.
This is why you should get your ENERGY STAR windows from Karoly Windows & Doors! At Karoly, we specialize in doing every window installation the right way. We only ever use in-house employees for our installation work—we never outsource to a third party.
This way, you know that you’re getting top-grade window installation work from a trusted team of experts.
Why is subcontracting work such a problem? Because subcontractors are often not licensed as specialty contractors who know how to properly install new windows. Or, they may do the work in a slipshod manner, compromising the energy efficiency of the window.
By using in-house, W-2 employees to install windows, Karoly can maintain a consistent standard of quality for window installation and give you the best-in-class service you both need and deserve!
Reach out today to get a quote for ENERGY STAR window installation!
