One of the most common reasons to replace existing windows is to increase the energy efficiency of your home. This reduces your heating and cooling bills and lowers greenhouse gas emissions. Pella windows are up to 74 percent more energy efficient1. You’ll notice the savings immediately. Poorly performing windows and doors cause heating and cooling loss in your home. Don’t throw money out the window!

Be sure to look for these energy-efficient features:

Multiple panes of glass

Double-pane glass insulates almost twice as well as single-pane. Triple-pane glass maximizes your energy efficiency.

Low-E (Low-emissivity) glass coatings

These are layers of thermal protection inside insulating glass that help:

  • Reflect summer heat and retain interior cooling.
  • Reflect winter cold and retain interior heat.
  • Block harmful UV rays to help prevent fade damage.

Argon (inert gas) between the glass panes

Argon2 is a natural, colorless, nontoxic gas that’s denser than air. It adds layers of insulation to further reduce the transfer of heat or cold, making your home even more energy-efficient and comfortable.

ENERGY STAR qualified

Pella products offer the energy-efficient options that will meet or exceed ENERGY STAR® guidelines in all 50 states.3 American households are saving significantly on their energy bills by using ENERGY STAR certified products. Learn more about ENERGY STAR.

Pella’s InsulShield® energy performance glass

Pella InsulShield® energy performers include:

  • Advanced Low-E Insulating Glass with Argon
  • Designer Series® Advanced Low-E Insulating Triple-Pane Glass with Argon
  • SunDefense™ Low-E Insulating Glass with Argon

Look for energy-efficient window frames

  • Wood frames are excellent insulators — they conduct less heat or cold into your home. In fact, they insulate 1,800 times better than aluminum.
  • Fiberglass composite material offers the insulating properties of wood. It won’t expand and warp in the summer, or shrink and turn brittle during winter.
  • Vinyl multi-chambered frames reduce heat loss for added energy efficiency ― and they’re exceptionally easy to care for.
  • Aluminum is inexpensive and durable but has a poorer insulation rating, meaning the frames conduct more heat or cold into your home.

Tight seals

Windows and doors that don’t seal properly are drafty — affecting your comfort level and increasing your energy costs. Rest assured, Pella tests its products in state-of-the-art facilities to make sure they meet or exceed industry performance standards.

Quality installation

If installed incorrectly, your windows and doors may not operate properly. Proper installation will help prevent air infiltration and even costly water damage to your home.

The NFRC label

It’s the only reliable way to determine the entire window’s energy performance and to compare products realistically.
The National Fenestration Ratings Council (NFRC) is a nonprofit organization for the window industry that developed an energy rating system based on whole-unit product performance — not just the glass.

The U-Factor represents the rate of heat flowing out of a window or door in an hour. The lower the number, the better the glass insulates.
The Solar Heat Gain Coefficient (SHGC) rating measures the amount of solar radiation that enters as heat. The lower the number, the less heat the glass allows in.

1 Calculated based on NFRC ratings for a Pella Designer Series Advanced Low-E triple-pan wood window compared to a single-pane window in winter conditions.
2 High-altitude Low-E insulating glass does not contain argon gas in most products.
3 Some products may not meet ENERGY STAR guidelines in Canada. For more information, contact your local Pella sales representative or go to