Thermally Broken Windows: Key Benefits & Costs (Everything You Need to Know)

Since 1977, Demers Glass has helped Arizona homeowners and businesses make confident choices about their glass products. When it comes to windows, one of the most important innovations in energy performance and comfort is the use of thermally broken frames. This guide will walk you through everything you need to know about thermally broken windows—from how they work to whether they’re worth the investment.

What Are Thermally Broken Windows?

Thermally broken windows are built with a thermal barrier inserted between the interior and exterior sections of the window frame, often made from aluminum. This barrier, typically a material like polyurethane or polyamide, prevents heat and cold from passing through the highly conductive metal frame.

As Cantera Doors explains, this disruption of the thermal path significantly reduces energy transfer. By minimizing conductivity, thermally broken windows help maintain interior temperatures, reduce energy costs, and eliminate cold spots near the window.

Why it matters: Aluminum is a strong, durable material, but it conducts heat very efficiently. Without a thermal break, outdoor temperatures transfer directly into the home. In Arizona's extreme climate, that could mean a major load on your HVAC system.

What Are Non-Thermally Broken Windows?

In contrast, non-thermally broken windows are made from continuous materials—usually metal—without an insulating layer. This makes them more affordable but far less efficient in terms of thermal performance.

You may notice:

Warm or cold window frames depending on the season
Drafts or hot/cold spots near the windows
Increased condensation on the interior side

These types of windows are more common in older construction or buildings that prioritize initial cost over long-term performance.For an overview of materials and how glass type can affect performance, you may also want to explore our guide on the best glass for your home windows.

Key Benefits of Thermally Broken Windows

1. Energy Efficiency

Perhaps the greatest benefit is their performance in regulating indoor temperatures. According to Brennan Enterprises, thermally broken frames can reduce heat loss by up to 60% compared to traditional aluminum.

This translates to real-world savings, particularly in climates with extreme temperature swings.

Want to go deeper? Check out our full energy-efficient windows guide.

2. Improved Indoor Comfort

It's also easier to maintain consistent thermostat settings, lowering your HVAC usage.

3. Condensation Reduction

Interior window condensation can lead to mold, mildew, and frame deterioration.

4. Better Sound Insulation

While not a direct goal, the break in the frame structure also reduces sound vibrations. Combined with double or triple glazing, thermally broken windows can contribute to a quieter home environment.

5. Durability and Longevity

By avoiding the stress caused by extreme temperature fluctuations and moisture, these windows maintain their integrity longer. They resist warping, corrosion, and wear much better than single-material frames.

When Should You Choose Thermally Broken Windows?

If you're in Arizona or any region with intense sun, hot summers, or cold winters, thermally broken windows are a smart choice. They are ideal for:

Homes undergoing major renovations or energy-efficient upgrades
New builds seeking LEED or Energy Star certifications
Modern or minimalist homes with large glass panels

They are especially impactful when combined with full whole-house window replacement, allowing for a cohesive, efficient design.

How Much Do Thermally Broken Windows Cost?

The upfront cost is typically 25–40% higher than standard aluminum or vinyl-framed windows. According to Portella Steel Doors and Windows, this price reflects not just material quality, but the engineering and assembly precision involved.

Factors that influence cost include:

Frame material: Aluminum vs. steel
Window type and size: Fixed, operable, or custom
Glazing: Double vs. triple-pane, Low-E coatings
Labor and installation

Want to learn more about material comparisons? Read our take on Pella vs. Andersen Windows.

Are Thermally Broken Windows Worth It?

In short: yes, especially over the long term. Panda Windows notes that the initial cost pays off through lower energy bills, better indoor air quality, and improved comfort.

Additional ROI comes from:

Boosted resale value
Lower HVAC maintenance
Long product lifespan

They’re also ideal for cold climates like Northern Arizona.

Thermally Broken vs. Non-Thermally Broken: Side-by-Side Comparison

Environmental Impact

Thermally broken windows not only improve indoor efficiency—they reduce a building's carbon footprint. Lower energy usage = fewer greenhouse gas emissions. They're often used in sustainable building designs and Passive Houses.Looking for more eco-upgrades? Check out our guide on window tinting to further reduce solar heat gain.

Maintenance Tips

Clean frames regularly to prevent dirt buildup
Inspect seals and thermal barriers annually
Lubricate hardware to prevent corrosion
Check glazing for signs of fogging or seal failure

Pro tip: If you're upgrading, consider replacing old fireplace glass doors at the same time for a full-home energy tune-up.

FAQs About Thermally Broken Windows

Q: Can I retrofit my existing windows with thermal breaks?
A: Typically no. Thermally broken designs are built into the frame itself and require full window replacement.

Q: Are thermally broken windows only for aluminum?
A: While most common in aluminum and steel, some composite and fiberglass systems also use thermal breaks.

Q: How long do they last?
A: With proper installation and maintenance, thermally broken windows can last 30 years or more.

Q: Do they qualify for energy rebates or tax credits?
A: In many states, yes—especially when part of a full efficiency upgrade. Consult local programs or ask our team for assistance.

Why Choose Demers Glass for Your Window Upgrade?

As a family-owned business with over 45 years of experience, we pride ourselves on helping customers make informed, confident decisions. Our team understands the Arizona climate and can recommend the right glass solutions to fit your lifestyle and energy goals.

Trusted experts in residential and commercial glass
High-quality thermally broken window systems
Precision installation backed by warranty
Friendly, no-pressure consultations

Whether you're replacing a single unit or planning a full home remodel, Demers Glass is here to help. Explore our window replacement guide to get started.