Last month, the glass industry once again united to quash a proposal that would have reduced glass on buildings by 25 percent in the ASHRAE 189.1 standard. This was the second such attack on glazing area that the industry has defeated at ASHRAE. Each bout in this “Battle for the Wall” shines light on the heart of the issue: a view by many in the building community that glass is simply a poor energy performer. The industry has been fighting a battle for the wall, when perhaps it should be fighting the war of perception.
The primary driver of these proposals to reduce window to wall ratio at ASHRAE is “the misguided opinion that ‘windows are just poor performing walls,’” says Tom Culp, owner of Birch Point Consulting LLC, and code consultant for the Glass Association of North America and the Aluminum Extruders Council. Culp represented the glass and glazing industry during the recent ASHRAE hearings.
“It is a challenge to change these perceptions, many of which were formed years or even decades ago when, in all honesty, glass was a fairly poor performer in terms of energy efficiency compared to other wall materials,” said Glenn Miner, director, construction, PPG Flat Glass in “The New Era,” from October 2013 Glass Magazine.
Proponents of less glass on buildings often promote a narrow view of energy performance. They only look “at something like R-value, without considering how high performance windows can actually outperform walls when considering daylighting, passive solar gains, etc.,” Culp says. “There is a tendency to just look at the output of a computer model and see a small difference in BTUs without thinking about real world design, and why people put windows in buildings. Instead of minimizing windows, they should leave the window area decisions to the building and daylight designers, then focus on putting in the best window possible.”
The industry has an opportunity to harness the momentum from the recent victory at ASHRAE to work as a unified group to shift this perception by many that glass is a poor energy performer. The recent fight at ASHRAE brought together 126 individual companies and 13 associations to support the interests of the glass industry. Those voices working together could make a difference changing minds about glass performance.
First and foremost, the industry needs to promote the energy and health benefits of glass and glazing (see “The New Era” for more on this front). Obviously, a reduction in glazing would harm the glass industry. But, it would also harm building occupants, while limiting potential energy savings.
The industry should educate about best design practices when it comes to glass and glazing. There is such thing as too much glass. Or, perhaps more accurately, the wrong glass type used too extensively in the wrong place on a building. Misuse or overuse of glass can create inefficient and uncomfortable buildings, while potentially providing fodder for the proponents of less glass (see “Power of Perception,” from December 2010 Glass Magazine for more on this).
And, the industry needs to keep improving the energy performance of its products. As Scott Thomsen, former president of the Global Flat Glass Group, Guardian Industries, said during his keynote talk at last year’s BEC Conference, “we need to improve energy efficiency or lose surface area.”
These are not groundbreaking ideas. Proposals to change perceptions and promote performance are often discussed at industry meetings and in industry publications. But, it’s time to bring them to the building community at large to prevent future battles. “We cannot assume [WWR won’t come up again], and proposals to tie requirements to window area could pop up again in the future,” Culp says. “We can’t just go back to ignoring the issue again. … The discussion is not over, and people need to stay engaged.”
Get involved with industry trade organizations. Keep informed. And promote performance through smart design. The industry has won the most recent battle; now it’s time to win the war.
Devlin is editor of Glass Magazine. Write her at email@example.com.