Best Energy Efficient Windows 2026
- The Wacky Window Woman
- Jan 7
- 4 min read
Updated: Jan 8
When the time came for my husband and I to start shopping for replacement windows, we knew we wanted a high performing window, but we really didn't know what to look for. Most of us have heard of Energy Star as it pertains to home improvement and appliances, but how does it impact ratings of replacement windows?
What we learned from Joe at Virtual View Windows, is that Energy Star rated windows are yesterday's news. What you want in 2026 is Energy Star, 7.0, Most Efficient Rated Windows. Virtual View, the company we ultimately chose for our Window Replacement is a nationwide company that conducts the sales process from Quote to Contract Virtually. No weird sales guy sitting at your dining room table for hours.
You can reach out to Joe directly with photos, numbers of windows, approximate sizes, material of exterior of your home and year it was built. He'll work up a quote and send to you via email so you can review in the comfort of your own home. You can even request a Zoom call to answer any questions and for him to demo the features of his Alside Mezzo Window.
Window Ratings Explained
As the Wacky Window Woman and in my quest to gather energy ratings and pricing for my Wacky Window Woman Price Comparison chart, I had to do a crash course in Energy Ratings.
On my chart I've broken down the ratings for each of the ten window companies that I invited into my home for a quote. In the chart, I've highlighted:
Energy Star 7.0
Air infiltration Ratings
U-factor Ratings
Solar Heat Gain Coefficient (SHGC)
Energy Star Window Ratings
Energy Star ratings for windows are crucial because they identify products that significantly reduce energy consumption, lowering utility bills by an average of 12% annually. These ratings ensure better insulation, improved home comfort by reducing drafts and condensation, and protection for interior furnishings from UV damage, all while adhering to climate-specific performance standards.
Window Air Infiltration (Air Leakage) Rating
Air infiltration, or air leakage, is crucial for replacement windows because
it directly dictates energy efficiency, comfort, and, in some cases, indoor air quality. High air infiltration increases heating/cooling bills and causes drafts, while low rates ensure airtight performance, with ENERGY STAR® recommending a rate of
≤0.30is less than or equal to 0.30 ≤0.30 cfm/sqft.
U Factor Windows Rating
U-factor is critical to replacement windows because it measures insulation performance, directly affecting energy bills and home comfort by quantifying the rate of heat transfer. A lower U-factor (ideally 0.30 or lower) signifies superior insulation, keeping indoor heat in during winter and blocking outdoor heat during summer.
Window SHGC (Solar Heat Gain Coefficient)
Solar Heat Gain Coefficient (SHGC) is critical for replacement windows because it dictates how much solar radiation passes through the glass, directly affecting energy bills, indoor comfort, and HVAC load. A lower SHGC blocks heat in warm climates to reduce cooling costs, while a higher SHGC allows passive heat gain in cold climates to save on heating.
Are Triple Pane Windows Worth It?
So, here is the secret tip. In order to get high-performing windows and ensure they meet Energy Star 7.0, Most Efficient Ratings, you will have to upgrade to triple pane windows. You might be thinking, okay, so what's the cost difference? Well not as much as you might think.
In most cases the cost to upgrade from double pane to triple pane can average from $55 to $100 per window.
Best Energy Efficient Windows 2026
After interviewing ten different window companies, my husband and I chose to go with Virtual View Windows, powered by McCloud Windows in Columbus, Ohio. Virtual View sells the Alside Mezzo Window. We chose to upgrade to triple pane to get the highest energy efficiency that we could get within our budget.
They were not the least expensive, but when we baked the energy ratings into their final quote, they were the best value. Second, the fact that we could conduct the entire sales process from quote to contract virtually, was heavenly. It was so great to not have to let a sleezy sales guy into our home for two or three hours knowing that at the end of it, he was going to hound us to sign on dotted line.
Then when you add to that Alside gives you two warranties. One for the window product and second warranty for labor. No finger pointing here.
Joe was very low key. He has a great window at a fair price and he knew it. There was no need to put pressure on us which allowed us to come to a decision on our own.
