Why Window Energy Ratings Matter for Your Home

When it comes to making your Calgary home more energy efficient, your windows play a bigger role than you might think. The right windows don’t just add style—they help keep your home comfortable year-round, lower heating and cooling costs, and even reduce your environmental impact. That’s why understanding window energy ratings is so important.

Understanding Energy Ratings for Windows

Energy ratings are a standardized way to measure how well a window performs. They show how effectively a window keeps heat inside during the winter, blocks unwanted heat in the summer, and allows natural light to pass through without causing big temperature swings. For Calgary homeowners—who deal with freezing winters and warm summers—choosing windows with the right energy ratings is essential. Energy-efficient windows are designed to handle these extremes, keeping your home more comfortable year-round.

Key Factors in Window Energy Efficiency

Two of the most important window performance ratings are the U-Factor and the Solar Heat Gain Coefficient (SHGC):

• U-Factor: Measures how well a window insulates. The lower the number, the better it keeps heat inside.

• SHGC: Measures how much solar heat enters through the glass. Lower values help keep homes cooler in the summer.

For Calgary’s climate, selecting windows with the right balance of U-Factor and SHGC can maximize comfort and reduce energy costs.

The Role of Energy Star in Choosing Windows

Energy Star® is a well-recognized symbol for energy efficiency. Windows with this certification meet strict government standards and are tested to deliver proven energy savings. Choosing Energy Star-rated windows is a reliable way to ensure your home renovation supports efficiency, comfort, and sustainability.

That said, it’s worth noting that Energy Star does not recognize higher LoE coatings (like LoE-366) as “efficient.” This standard was created as a blanket guideline for all of Canada, but it doesn’t always reflect Calgary’s unique climate.  In reality, the higher the LoE number, the more heat and UV rays the glass will block—helping keep your home cooler in the summer. Since Calgary is one of the sunniest cities in the country, and most homes now have central air conditioning, choosing windows with a higher LoE coating can be a smart choice—especially for south-facing windows or areas that get the most direct sunlight.

Benefits of Investing in Energy-Efficient Windows

Upgrading to energy-efficient windows goes beyond saving on utility bills. Additional benefits include:

• Less strain on your heating and cooling system
• Increased home value and market appeal
• A smaller carbon footprint and healthier indoor air quality.

Simply put, energy efficient windows are an investment in your home’s comfort, efficiency, and long term value.

Contact S.I.S. Exterior Renovations Today

If you’re thinking about upgrading or installing new windows, understanding energy ratings is the best place to start. At S.I.S. Exterior Renovations, we offer high-quality, energy-efficient window solutions tailored to your home, your comfort, and Calgary’s unique climate. Our team is here to guide you through the options and help you choose windows that fit your energy goals, style, and long-term needs.

To learn more about how we can assist with your exterior renovation needs, including energy-efficient window installation, please call us at (403) 640-1334 or fill out our online form today. We’re here to help you make your home more comfortable, efficient, and environmentally friendly.