Here are a few of the most notable changes that are included in this update:

• In all climate zones, the criteria for meeting ENERGY STAR requirements have changed with very stringent changes in the Northern and North-Central climate zones — see tables below to understand the changes in each climate zone.
• Version 7.0 brings the most stringent criteria ever with a Northern zone U-Factor of ≤ 0.22 for windows and ≤ 0.26 for patio doors.
• Also in the Northern zone, for the first time, there is a minimum Solar Heat Gain Coefficient (SHGC) requirement for windows of ≥ 0.17. ENERGY STAR continues to allow equivalent energy options for windows in the Northern climate zone where a higher U-Factor can be used with a minimum SHGC. See tables below for details on requirements for prescriptive and equivalent options.
• In the North-Central climate zone, the U-Factor has also changed significantly from ≤ 0.30 to ≤ 0.25.
• In the South-Central climate zone, there has been a more moderate change in window U-Factor from ≤ 0.30 to ≤ 0.28.
• In the Southern climate zone, the window U-Factor requirement has changed significantly from ≤ 0.40 to ≤ 0.32.
• The SHGC requirement for windows in the South-Central and Southern climate zones has been lowered from ≤ 0.25 to ≤ 0.23.
• For doors, particularly the > ½ lite category that glass patio doors fall under, the U-Factor criteria has changed from ≤ 0.30 to ≤ 0.26 in the Northern and North-Central climate zones.
• The climate zone map has also changed most notably in the West, see California and Nevada. This has resulted in changes to all four of the ENERGY STAR climate zones, so pay close attention when understanding the right climate zone in your area.

Need a quick review of performance measures?

If you’re trying to remember what U-Factor and SHGC mean, here’s what to know about these measures as they apply to windows and doors:

• U-Factor: This is a measure of insulation, or how well a window or door keeps energy (heat) from escaping. The less heat loss through the window or door, the more energy efficient the window or door. U-Factors are measured in British Thermal Units (BTUs) per hour square foot degree Fahrenheit and abbreviated as BTU/hr·ft²·°F. They can range from 1.2 (worst performing) to 0.20 or lower (best performing). Lower U-Factors can often improve comfort and lower heating costs.
• SHGC: This is a measure of how much heat is transmitted through a window or door from the sun. It’s measured on a scale from 0 to 1 and expressed as a decimal point. The lower the number, the less heat gain through the window or door. Less heat gain can help improve comfort and lower cooling costs.
• Air leakage: This is how much air leaks through the window or door assembly itself. It’s not a measure of air leaking around the unit due to sealing deficiencies that might occur during installation. Air leakage is measured in cubic feet per minute per square foot of the window or door’s area. A lower number means less air leakage through the window or door.
• Visible Light Transmittance (VLT): This is a measure of how much sunlight passes through a window or door. It’s measured on a scale from 0 to 1 with higher numbers indicating that more light comes through the window or door. More layers of glass and different Low-E glass coatings — as well as the width of the window sash and frame, or door panel and frame — can lower the VLT of a window or door.

One unique aspect of meeting ENERGY STAR criteria for windows in the Northern zone is that there are two options to qualify: a primary prescriptive path or an equivalent energy performance path. Again, only the Northern climate zone allows two options and only for windows. Patio doors (> ½ lite category) in the Northern zone must follow the prescriptive path.

The prescriptive path means the window product must meet a U-Factor value that’s ≤ 0.22 and an SHGC value that’s ≥ 0.17. The second path, the equivalent energy performance path, allows for a higher U-Factor if there’s a higher SHGC to go along with it — see the window criteria table above for exact values.

In North-Central, South-Central, and Southern climate zones, there are more options across a variety of product lines for meeting requirements with dual-pane glass and coatings. Limited dual-pane glass options will be able to meet requirements in the Northern climate zone.

• Northern climate zone: Although there are more limited dual-pane window products that will meet requirements for this zone, in some cases adding PassiveSun® glass with HeatLock® technology will provide the insulation needed while also allowing for higher SHGC. This combination of coatings has recently been expanded and is now available across all our window and patio door product lines. In addition, the 400 Series Tilt-Wash Double-Hung Window can meet requirements with the addition of a factory-applied performance panel and the right combination of glass coatings.
• North-Central, South-Central, and Southern climate zones: In many cases, SmartSun glass with HeatLock technology will help a dual-pane window meet requirements.

There are more options available with gliding patio doors, including several options that work in all four climate zones. In the South-Central and Southern climate zones, there are a variety of options available across a variety of product lines. Options are a bit more limited for the Northern and North-Central climate zones.

• All climate zones: Four gliding patio doors and one hinged patio door can meet requirements in all four climate zones. The 200 Series Narroline® Gliding Door, the 100 Series Gliding Door, the Perma-Shield Gliding Door, and the A-Series Gliding Door with SmartSun glass and HeatLock technology will lower both U-Factor and SHGC to meet requirements. In addition, the A-Series Hinged (Outswing) Patio Door with the same dual-pane glass construction and same combination of glass coatings (SmartSun glass with HeatLock technology) can meet requirements across all four climate zones.
• Northern and North-Central climate zones: Options include gliding patio doors from the 100 Series and 200 Series product lines with Low-E4® glass and HeatLock technology or SmartSun glass and HeatLock technology.
• South-Central and Southern climate zones: Options include both gliding and hinged patio doors from the 100 Series, 200 Series, 400 Series, and A-Series product lines with SmartSun glass or SmartSun glass with HeatLock technology.

Under the Inflation Reduction Act (IRA) of 2022, there is an energy efficient home improvement tax credit available. Qualifying window and door products may be eligible for up to 30% reimbursement from 2023 through 2032. Windows that meet ENERGY STAR’s Most Efficient category and patio doors that meet ENERGY STAR version 7.0 criteria for their climate zone qualify.

Note, ENERGY STAR Most Efficient criteria will change for 2024. The requirements listed in the table below will become effective January 1, 2024.