Understanding Energy Efficiency Ratings for Windows in Louisville

Energy efficiency standards can be a puzzle for some and another language for others. If you’re not well-versed in energy lingo, understanding what you're getting can be very confusing when you buy into new windows.

Replacement windows are one of many ways to raise your home's energy efficiency and save a few bucks on energy costs. But those tricky standards can prove to be confusing for the uninitiated. That’s why Weber Windows is here – to educate and inform!

But First, An Energy Efficiency Primer

ENERGY STAR standards measure and rate the performance of windows in terms of energy efficiency.

Insulation properties are measured by what’s called the U-factor. The U-factor measures the heat transfer of a window. A lower U-factor number means your window is better insulated. The solar heat gain coefficient, or SHGC, also shows the power of your window’s heat-blocking capabilities. Standards also measure visible transmittance, or VT, showing how much light a window allows. Then there’s air leakage, measuring the air that passes through cracks in crevices in your window.

When choosing your new windows, you and your window installers should remember these values.


ENERGY STAR was created to help consumers better understand how energy efficiency can help lower their power consumption. Through the ENERGY STAR program, started in 1992 as a joint venture between the Environmental Protection Agency and the U.S. Department of Energy, consumers now have the edge in discovering products that help reduce environmental impact. Thousands of home improvement products carry the ENERGY STAR seal, informing consumers that the product seeks to lower energy consumption.

What You Should Seek in Window Energy Efficiency

Generally, customers looking for energy-efficient windows must seek a product with a good mix of U-factor, SHGC, VT, and air leakage values.

Seek windows with a U-factor and SHGC of around 0.25. This value must be lower than the standard of 0.3 for air leakage. As for VT, it will depend on how much natural light you want in your home.

Call Weber Windows for More!

If you’re searching for new energy-efficient windows, Weber Windows is your trusted dealer and window installation expert in Louisville, KY. We have many reliable brands of windows designed to help you get the most from a lower energy bill. Contact us today to learn more!