Demystifying Industry Terms about Energy-Efficient Windows

When buying energy-efficient windows, it’s impossible not to encounter industry terms. You may think they’re just there to make products sound impressive, but it actually pays to decipher them.


Energy-Efficient Windows

To help you understand the language of modern fenestration technology, Jones and Associates wants to shed light on these key, generic terms:

Insulated Glass

Insulated windows comprise multiple panes with an insulative gas to resist heat transfer. In North America, double glazing is the standard in all regions, which are units with two sheets of glass. Compared with ordinary windows, insulated units can keep your home comfortably warm in the winter.

Our company carries energy saving windows under the Simonton Platinum Prism Collection. The insulated glass of our units is 1 inch thick with an argon gas for fill. The exceptional combination of thickness and energy efficiency allows our products to outperform their best counterparts.

Low-E Glass

Shorthand for low-emissivity, Low-E coatings are thin layers of protection that block most of the solar energy that hits the glass surface. They keep your home from overheating, especially at the height of summer.


When shopping for energy saving windows, one of the ratings to look for is U-Factor. It refers to the product’s ability to insulate heat. This metric is expressed in numbers ranging from 0.20 to 1.20; the lower the digit, the better.

U-Factor is often used interchangeably with R-value, which is a popular insulation metric for walls and ceilings. Unlike U-Factor, a higher R-value means better thermal performance. The two terms are practically the same except U-Factor is more common in rating fenestration products.

Solar Heat Gain Coefficient (SHGC)

SHGC measures how well the product can resist heat gain. Expressed in numbers ranging from 0 to 1, the lower the number, the better. In hot climates, energy saving windows have an extremely low SHGC rating.

Visible Transmittance (VT)

VT pertains to the capacity of the window to admit natural light. Also expressed in numbers ranging from 0 to 1, but a higher value means a more positive rating.

At Jones and Associates, all our Simonton Platinum Prism windows are certified by ENERGY STAR® to meet the energy efficiency requirements of our region. Talk to us about your project in Midland, Odessa, and Lubbock, TX. Call us today at (806) 686-1380 to schedule your FREE, in-home consultation.

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