Replacing your windows or doors is a big investment, and "ENERGY STAR" is one of the first labels you'll run into while you're comparing options for replacement windows and doors. Here's what the label actually certifies, how a window or door earns it, and what it means for a home in Northern Virginia's climate.
What does the ENERGY STAR label actually mean?
ENERGY STAR is a certification program run jointly by the U.S. Environmental Protection Agency (EPA) and Department of Energy. A window or door earns the label because it's been independently tested by the National Fenestration Rating Council (NFRC) and meet specific performance thresholds for your climate zone. Northern Virginia falls in the Northern-Central climate zone, which sets its own U-factor and solar heat gain coefficient (SHGC) requirements, different from what a window would need to certify in, say, Florida or Arizona.
In plain terms: an ENERGY STAR label tells you a product has been tested, not just marketed.
The history of ENERGY STAR
ENERGY STAR is an initiative of the Environmental Protection Agency (EPA) to identify products that meet government standards for energy efficiency, part of a coordinated effort to drastically reduce greenhouse gas emissions. When the ENERGY STAR voluntary labeling program was first introduced in 1992, it only applied to computers and monitors, but since then it has come to encompass some 70,000 products across 75 residential and commercial categories (as of 2019). Of those, only about 3,000 (4 percent) garnered the ENERGY STAR "Most Efficient" designation for exemplary performance.
Throughout its history, ENERGY STAR has implemented a number of programs and resources to assist homebuilders, homeowners, and residential contractors — for both new construction and existing structures. ENERGY STAR new constructions in the single-family, multi-family, and manufactured home categories, on average, exceed building code standards for energy efficiency by 20 percent.
For current homeowners looking to improve their energy efficiency, check out the following:
- ENERGY STAR Home Advisor: self-assessment and customized recommendation tool
- ENERGY STAR Yardstick: learn how you measure up to similar homes in total energy consumption.
- Home Energy Knowledge Center: Find certified contractors, installers, and HVAC specialists.
How windows and doors earn an ENERGY STAR rating
For a window or door to even be considered for the ENERGY STAR label, it must:
- Come from a certified ENERGY STAR partner manufacturer
- Pass the National Fenestration Rating Council's (NFRC) testing, certification, and verification process.
- Return from the NFRC with ratings that meet guidelines established by the EPA.
Every ENERGY STAR window and door is tested and labeled with a few core NFRC ratings:
- U-Factor: how well the product resists heat transfer. Lower is better; this is the number that most directly drives winter heating performance.
- Solar Heat Gain Coefficient (SHGC): how much solar radiation passes through as heat. Lower SHGC means less unwanted heat gain in summer.
- Air Leakage (AL): how much air passes through the assembly. Lower is tighter.
A product qualifies by meeting the EPA's threshold for both U-Factor and SHGC in its specific climate zone which is why a window certified for the Pacific Northwest isn't automatically certified for Virginia, and vice versa. Manufacturers submit products for independent NFRC testing, and the results are printed right on the NFRC label affixed to the window or door so you can verify the numbers yourself rather than taking a sales claim at face value.
Optimal ENERGY STAR window ratings vary slightly by climate, especially in regard to SHGC. Hodges Windows and Doors services Northern Virginia and the D.C. Metro Area, which both fall within the NFRC's North-Central Climate Zone. Here, windows should have a U-Factor less than or equal to 0.30 and a SHGC less than or equal to 0.40.
Doors are evaluated according to their glazing level, or the percentage of total surface area that is glass. Opaque doors (no glass) should have a U-Factor less than or equal to 0.017, doors that are less than half glass should have a U-Factor and SHGC both less than or equal to 0.25, and doors that are more than half glass should follow the same climate-prescribed ranges as windows.
How to know you're getting a genuine ENERGY STAR product
The label itself is the proof! Look for the blue ENERGY STAR mark and the NFRC performance label on the product, not just a claim in a brochure. Many of the window and door lines we install, including our ProVia products, carry ENERGY STAR certification, and our team can walk you through which specific models on our showroom floor meet the label and what their NFRC numbers are for your project. That's the kind of detail worth confirming in person rather than guessing from a spec sheet.
Why ENERGY STAR products matter for a Northern Virginia home
Ashburn, Falls Church, Leesburg, and the rest of Northern Virginia see real seasonal swings, from humid summers to cold winter nights, which is exactly the condition ENERGY STAR's climate-zone-specific testing is built around. A window or door that's only rated for a mild climate won't perform the same way here. According to ENERGY STAR, replacing single-pane windows with ENERGY STAR certified units can lower a home's energy bills by an average of up to 13% nationwide.
All Hodges Windows and Doors suppliers are ENERGY STAR darlings, consistently rating high for energy-saving window features such as non-conductive framing materials, multiple panes with low-emissivity coatings, and non-reactive gas fills to maximize efficiency. This year we are especially proud to be associated with ProVia, winner of the 2020 ENERGY STAR Partner of the Year - Sustained Excellence Award. Thanks to ProVia and ENERGY STAR's thousands of other partners, American families and businesses have saved more than 4 trillion kilowatt-hours of electricity and reduced greenhouse gas emissions by 3.5 million metric tons since 1992.
These are savings that benefit both our bank accounts and our planet.
Not sure which ENERGY STAR certified windows or doors are right for your home?
Schedule your free estimate with Hodges, or visit our Asburn or Falls Church showroom to see NFRC-labeled products in person.
