Navigating Skylight Jargon & Technical Terms

By Skylight Experts

Demystifying the jargon

The skylight industry has its own language. Terms like “thermally broken frame,” “low‑E glass” and “argon‑filled glazing” sound technical, yet they describe innovations that improve comfort and energy efficiency. Understanding these features helps you compare products and choose the best skylight for your home.

Thermally broken frames

Standard metal frames conduct heat rapidly, allowing outdoor temperatures to penetrate indoors. To reduce heat flow, a thermal break — an insulating plastic strip — is placed between the inside and outside parts of the frame. This design is common in modern aluminium skylights. According to glazing experts, thermally broken frames can reduce heat loss by up to 60 % compared with conventional metal frames. The result is warmer rooms in winter, cooler spaces in summer and fewer drafts near the window.

Double, triple and gas‑filled glazing

Glazing refers to the layers of glass in a skylight. Double‑glazed units use two panes of glass separated by a spacer bar. The space between the panes is filled with air or an inert gas like argon, which is more insulating than air and reduces heat loss. Triple glazing adds a third pane, providing even better insulation and sound reduction. While triple glazing costs more, it can be worth it in very cold or noisy environments.

Low‑E coatings and warm edge spacers

Low‑emissivity (low‑E) glass has a microscopically thin metal oxide coating on one surface that reflects heat back into the home while letting visible light through. This coating reduces heat loss in winter and minimises solar gain in summer. Warm‑edge spacers — non‑metal materials separating the panes — further improve insulation and reduce condensation around the glass edges.

Putting it all together

When evaluating skylights, look for thermally broken frames combined with low‑E, argon‑filled double or triple glazing. These features work together to deliver high insulation (low U‑values) and better comfort. Ask your installer to explain the U‑factor (how easily heat passes through) and the Solar Heat Gain Coefficient (SHGC) for each product so you can make an informed choice.

FAQs

Q: What is a thermally broken frame?
A: It’s a frame that has an insulating strip between the inner and outer parts to reduce heat transfer. Thermally broken frames can cut heat loss by up to 60 %.

Q: Is triple glazing always better than double glazing?
A: Low‑E glass has a thin coating that reflects heat back into the room while still letting in daylight, improving energy efficiency.

Q: Is triple glazing always better than double glazing?
A: Low‑E glass has a thin coating that reflects heat back into the room while still letting in daylight, improving energy efficiency.