Thermally Broken vs Non-Thermally Broken Frames: What You Need to Know for Hurricane Zones

This came up in comments on one of my posts, since I usually reference non-thermally broken, non-insulated laminated glass in my detailing work.

Miami-Dade has led the nation in hurricane building codes for over 25 years, and it’s a hot, tropical climate. Most of the hurricane-tested window and door products were developed in the South Florida market using aluminum for strength and durability — not thermal performance. But as these products are now used in colder regions (like New England), more thermally broken versions have gone through hurricane testing.

I’ve been working on a comprehensive overview of hurricane-tested systems that are viable for luxury homes, and thermal break availability is becoming a key filter — especially for colder climates or mountain homes where energy codes are stricter.

Thermally broken frames are more expensive due to their construction: two separate extrusions joined by a non-conductive break. Each extrusion is painted separately, assembled, and tested — adding labor, complexity, and cost.

So while non-thermally broken systems may be standard in South Florida, they may not meet performance expectations elsewhere. It’s not just about code — it’s about comfort and long-term performance.

Thermally broken vs non-thermally broken frames