Upgrade To Energy-Efficient Windows And Doors—Save On Bills And Stay Comfortable Year-Round!
At Lexmark Windows & Doors, energy efficiency isn’t an upgrade—it’s built in. Every window and patio door features advanced LoĒ³-366 glass, Duralite spacers, & other featuers to keep your home cooler in the summer, warmer in the winter, and shielded from UV damage. Our partnership with Cardinal Glass ensures superior performance, comfort, and cost savings, all backed by certified ratings from NFRC and Energy Star®.
LoĒ³-366 is a crystal-clear, energy-smart glass coating that blocks intense solar heat, reflects unwanted warmth, and still lets in beautiful natural light. It even outperforms traditional tinted glass used in hot climates, giving you a cooler home without sacrificing your view.
But this isn’t just a summer solution—it’s the perfect cold remedy too. During chilly months, the insulation of your windows plays a major role in how warm your home feels. Because glass makes up the majority of a window’s exposed surface, its temperature directly affects the temperature in your room. LoĒ³-366 keeps the interior surface of your windows warmer, helping maintain a cozy, consistent room temperature even in freezing conditions.
With 95% UV ray blockage, it also protects your furniture, flooring, and décor from fading. So whether it’s blazing hot or icy cold outside, LoĒ³-366 keeps your home comfortable, efficient, and looking its best all year long.
While glass gets most of the attention, the space between the panes plays a huge role in window performance—and that’s where Duralite spacers shine. Every Lexmark window comes equipped with Duralite, an advanced, non-metallic warm edge spacer designed for maximum insulation and energy savings.
Unlike traditional metal spacers that conduct heat and cold, Duralite uses a unique composite material and polycarbonate design that minimizes heat transfer. That means less energy loss, fewer drafts, and more comfort inside your home. These spacers are also engineered to improve condensation resistance, reducing the chances of foggy windows or moisture damage.
With a smooth, sleek black sightline and proven argon gas retention, Duralite spacers don’t just perform—they look great too. By keeping the heat out in the summer and the cold out in the winter, they help maintain a consistent indoor temperature and lower your utility bills.
It’s one of those details you don’t see—but definitely feel.
At Lexmark Windows & Doors, we don’t just say our products are energy efficient—we prove it. Every window and door we manufacture undergoes rigorous energy performance testing and earns certification through nationally recognized organizations like NFRC, Energy Star, FGIA, and AAMA.
The National Fenestration Rating Council (NFRC) provides a standardized way to compare the energy efficiency of windows and doors by rating U-Factor, Solar Heat Gain Coefficient (SHGC), Visible Transmittance (VT), and Air Leakage. These numbers tell you how well a product insulates, resists heat from the sun, allows in natural light, and prevents drafts.
In addition, all Lexmark products meet or exceed California Title 24 energy code requirements—one of the strictest in the nation—ensuring your home meets modern standards for energy conservation.
What does this mean for you? It means peace of mind. You’re investing in windows and doors that are proven to save energy, reduce heating and cooling costs, and keep your home comfortable year-round. When you see that certification label, you know you’re getting products that deliver real, measurable results.
Understanding how windows and doors impact your home’s comfort and efficiency starts with knowing how they’re rated. Every product’s performance can be broken down into measurable characteristics like U-Factor, Solar Heat Gain Coefficient (SHGC), Air Leakage, and Visible Transmittance (VT).
U-Factor measures how well your window insulates—lower numbers mean better insulation, especially important in colder climates.
SHGC tells you how much heat from the sun passes through the glass. A lower SHGC keeps your home cooler in hot weather, while a higher SHGC can help warm a space during the winter.
Air Leakage rates how drafty your window is. Tighter seals mean lower leakage and less energy loss.
Visible Transmittance (VT) is about how much natural light enters your home. Higher VT means brighter rooms without relying on artificial lighting.
These ratings aren’t just technical details—they help you choose windows that match your climate, lifestyle, and energy goals. The better the ratings, the more comfortable (and cost-efficient) your home will be year-round.
