Building code changes and increased stringency require the glass and glazing industry to stay informed, and code expert Tom Culp of Birch Point Consulting did just that at GANA’s Building Envelope Contractors (BEC) Conference earlier this week.
Monday, Culp gave a presentation about the latest in code requirements and where they’re headed.
He started by asking attendees, “Why should you care?” First, “knowledge of how the energy codes work can give you power to help your customer,” he said. Plus, “the specification starts from the code.” Also, awareness of new requirements can help in both suggesting the right products and recognizing product trends.
Culp pointed out that the industry is involved influencing codes and standards through groups such as Glass Association of North America (GANA), which is active with ASHRAE, ASTM, the International Code Council (ICC), the National Fenestration Rating Council, and more.
The presentation covered overall energy and green code trends, including increased adoption and enforcement of the codes. “Even where code enforcement is lax,” Culp said, these changes will still be seen in specification and product offerings.”
Increased stringency in base energy codes is also another trend, as well as the continued expansion of green codes and standards such as LEED v4, ASHRAE 189.1 and the International Green Construction Code (IgCC).
Culp spent focused on how spandrel is addressed in the energy codes. The spandrel area is considered an opaque wall and must meet either the prescriptive wall R-value or U-value requirements. Additionally, California’s Title 24, in particular, has a minimum insulation requirement where the entire curtainwall—both the vision and spandrel areas—must have an area-weighted average of a <0.28 U-value. Culp said there are “some technical problems with this” and that he is filing comment on behalf of GANA and the Aluminum Extruders Council regarding the issue.
The industry, meanwhile, scored a “huge victory” last year in defeating the ASHRAE 189.1 proposal to reduce the window area by 25 percent. Also, the 2014 edition of 189.1, published last fall, includes U-factor requirements 10 percent lower than the 2013 version, and solar heat gain coefficient (SHGC) 10 percent lower only on East and West sides—and no lower than 0.25.
The 2015 IgCC was also discussed, as final hearings and voting were completed last fall. Some highlights from the IgCC were strengthened daylighting requirements, easier language regarding Environmental Product Declarations and Life Cycle Assessment and U-value and SHCC requirements 5 percent lower than IECC rather than 10.
Culp also touched on the direction of the codes, noting that updated weather data shows climate zone boundaries will move in ASHRAE 90.1-2016 “and likely 2018 IECC.” He said they will affect local requirements and compliance, but not for two to 10 years, depending on local adaptation.
In terms of ASHRAE, he said there has been a “heavy emphasis” over the last seven months on updating the window criteria for the 2016 edition of 90.1, which includes the U-factor in Northern zones 4 through 8, as well as the SHGC in all zones, “but especially zones 0 through 3.”
Culp said flexibility needs to be included in the new window criteria to allow different technologies and trade-offs to use a higher window area. “If set too stringent, criteria will not encourage less glass, but could make it harder to use more glass,” he said.