Serious Materials, which recently acquired window innovator Alpen Energy Group, is tackling the wall’s most inefficient component with a new line of windows boasting unit R-values of 5 to 15. The company achieved this level, which is significantly higher than the R-2.5 to R-3 of a typical double-pane, low-E window, by reinventing the glass, the spacers, and the frame, says CEO Kevin Surace.

For the glass, the company leveraged the technology Alpen had developed for its award-winning windows. A layer of metal-sputtered Mylar, suspended between the glass panes, boosts center-of-glass R-values. The company developed two frame systems: a foamed PVC frame and a fiberglass frame with soy foam insulation. Finally, each window features an Eco Spacer that reduces heat loss at the edges of the glazings.

The company estimates the ThermaProof windows, which it will launch this fall, will run about $100 more per window, but that each will earn about $1,000 over its life in saved energy costs. Residential and commercial models will be offered.

R-value is an unfamiliar window measurement for most pros, but Surace says Serious Materials is looking to shift the conversation from the traditional center-of-glass U-values to full-frame R-values, which he says are more measurable and understandable.

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