Better minimum performance is not the best performance—nor is it the most efficient or greenest possible. Yet there are more ambitious standards that, like the U.S. Green Building Council's LEED program, set design standards as baselines for green construction. Jurisdictions can adopt the rules in the IGCC, CalGreen or ASHRAE Standard 189.1—another green building baseline—for a more aggressive local policy.

The result of all this on fenestration options has been twofold: Improving specification and field applications on the one hand, and encouraging innovations by product developers on the other.

“The IECC and IGCC are really driving how framing assemblies and glazing materials are made,” says Terry Zeimetz, AIA, CSI, CCPR, commercial marketing manager with Pella Commercial. “A new generation of fenestration systems is available with more internal chambers, triple glazing, multiple types of low-emissivity coatings, integral shading and other novel, energy-saving features.”

Source: www.commercialwindows.org/codesstandards_iecc_more.php#2012

“The codes are what really matter, and they don't distinguish between project types,” concurs Chris Dolan, director of commercial glass marketing with Guardian Industries. “Government buildings, institutional facilities and LEED-rated projects all have increasingly stringent energy requirements, so they are all seeking high-performance fenestration with the best-performing glass available.”

More critically, says Dolan and other fenestration experts, the codes and green standards rely on climate zone data to determine energy-efficiency requirements. They may also vary by jurisdiction, according to the Efficient Windows Collaborative (EWC), Minneapolis. “In the 2006 IECC and later, this variation is based on eight climate zones, with each county assigned to one climate zone,” according to the EWC. “However, older versions of the IECC specify 19 different climate zones.” Maximum U-factors and solar heat-gain coefficients (SHGCs) are given in the model energy codes and green-building standards. Skylights are treated separately, and have their own maximum values.

The development of novel fenestration systems, products and materials is the focus of this course. In order to put these innovations in proper context, a general understanding of the energy codes and green building standards—and their underlying building science—is critical.

For this Dept. of Veterans Affair Medical Center in Orlando, Fla., currently under construction, fire-rated glazing has been specified to improve safety and increase daylighting within. Photo courtesy of SAFTIFIRST