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Unlocking Energy Efficiency: A Closer Look at Energy Star’s Latest Guidelines for Windows and Doors

Greetings, Valley homeowners! In case you hadn’t heard, the new Energy Star 7.0 requirements are now in effect (as of October 23, 2023). We wanted to take the opportunity to break down what this means, if you’re shopping for replacement windows in the Metro Phoenix area.

The goal of Energy Star, as a government-backed symbol for energy efficiency, is to foster the use of more energy-efficient products, while diminishing greenhouse gas emissions and other pollutants. Under the new standards, your windows and doors will be more energy-efficient, keeping it more comfortable indoors during the summer months while using less electricity.

This is the first change to Energy Star requirements since 2006, and a significant stride towards a greener future, which takes all of us to make happen. Let’s welcome these changes with open arms, Phoenix!


Energy Star 7.0
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Understanding Energy Star 7.0 vs 6.0 for Windows & Doors

Let’s delve a little deeper into the new Energy Star requirements and how they differ from the old ones. Energy Star’s revised standards for windows and doors are more stringent, focusing on enhancing energy efficiency and sustainability more than ever before.

In contrast to the old requirements, the new standards emphasize reducing U-factor and Solar Heat Gain Coefficient (SHGC). The lower the number, the better. The U-factor, which measures the rate of heat transfer and tells you how well the window insulates, must be ≤0.32 in the Southern Zone, which is 0.08 less than the previous version.

Similarly, the SHGC, which indicates how much solar radiation a window lets in, will also have a lower threshold. It’s dropped by 0.02 to a minimum rating of ≤0.23. This means that new windows and doors will insulate better and allow less heat in, making your home more energy-efficient and comfortable, while helping you save on energy bills.

Better insulation, and less heat coming through the glass? We’ll take it.

But what about the Energy Star changes to doors, you might be thinking? It depends how much glass is included in the door. Opaque doors remain the same, with a U-Factor of ≤ 0.17 or lower. Doors that have a glass panel that is less than 50% of the door surface (half-lite) now require a ≤ 0.32 rating or lower for U-Factor and ≤ 0.23 for SHGC, and doors with 50% or more of the surface as glass  (think French doors or gliding patio doors) require a U-Factor of ≤ 0.28 or less, and a SHCG of  ≤ 0.23 or lower.

These numbers are 0.02 lower than the ratings for Energy Star 6.0.

The ratings for window and sliding glass door products Energy Star has deemed “Most Effective” are even more energy efficient, with a U-Factor of ≤ 0.20 and a SHGC of ≤ 0.25, and a NAFS performance grade ≥ 15.

How do these changes affect Phoenix area homeowners? Well, if you’re thinking about replacing your windows or doors, a great first step might be to choose product rated as Energy Star 7.0, not 6.0. This will help reduce your heating and cooling bills, and ease the load on your air conditioning unit (hence the electrical grid).

Since Arizona includes four different Energy Star zones, you’ll want to be sure this rating is specific to the Southern Zone, which covers the Phoenix Metro area.

The features and upgrades you select may determine whether a product qualifies as Energy Star 7.0, too, since it’s based on a specific combination of features. For example, you’ll need SunDefense LowE glass on a Pella window to qualify, along with Argon gas insulation and upgraded spacers and/or foam insulation between the panes of glass. If you skip any one of those three features, it won’t qualify.

As you talk about product with your salesperson, they’ll help you understand the energy efficient products and upgrades available, and the cost impact of those decisions.


Should You Go for Energy Star’s “Most Efficient” Recommendations?

Before you assume it’s best to go with Energy Star’s “best of the best” recommendations, which is recognized with the Most Efficient designation, you’ll want to discuss options with your salesperson to understand when an upgrade is worth the extra cost, and when it is not.

For example, if it’s a triple-paned window product, the increase in cost may not pay for itself by shaving money off your air conditioning bill. The difference might be so small that it takes forty years to break even. Not planning to stay in the home that long? You won’t recoup your money from the upgrade.

A good salesperson will be able to discuss this with you in detail, so you can make an informed decision.

Here’s one other change to consider: if you want to take advantage of the federal tax credit programs to claim new energy efficient windows on your taxes, you MUST purchase replacement windows and patio doors that have the Most Efficient certification. It’s required. You’ll want to compare that savings to the extra cost to determine if you feel it’s worth taking advantage of. The home must be the primary residence of the homeowner to qualify.

Questions? We know our product inside and out, and can help you choose the right windows for your home and budget. Schedule your free in-home estimate today!

(Published: Oct. 30, 2023)

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Please note that we install replacement windows and doors, but we don’t repair them or replace broken glass. Three-item minimum purchase, some doors excluded. Refer to our FAQ and warranties page for details.


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