Volume 47, Issue 11 - November 2012
The Path to Green
Since 2000, the U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) rating system has worked to create a new language in construction and design, one in which “green” refers not to glass’ color but to its performance. Also in 2000, the International Code Council (ICC) established its International Energy Conservation Code (IECC), a code that set a minimum for energy-efficiency performance in a commercial building.
LEED was always meant to go beyond the minimum; it was meant to encourage designers to push the envelope by providing a point-based system of options that would, presumably, improve the performance of the country’s building stock. The latest addition to the field of green requirements, the ICC’s International Green Construction Code (IgCC) likewise is meant to go beyond what is necessary in terms of sustainability and energy performance, steps beyond its sibling, the IECC. However, the question being asked is which green system is the one to follow? Will the adoption of the IgCC mimic LEED’s skyrocketing growth and, if so, what might be the impact on the glass and glazing industry?
What’s in a Code
As Tom Culp, owner of Birch Point Consulting in LaCrosse, Wis., explains it, the IgCC follows in the steps of the IECC. While the IECC references and incorporates ASHRAE 90.1, the Energy Standard for Buildings Except Low-Rise Residential Buildings, the IgCC incorporates the related ASHRAE standard 189.1, Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings. “They’re competing energy codes, but they also work together,” Culps explains of the ICC-ASHRAE relationship.
Culp says the IgCC is “similar to ASHRAE 189.1 in many ways, but it is a completely different organization and development process so there are a lot of things that are different. [IgCC] tends to be more performance-based. For example you’re only able to use the prescriptive path for buildings that are 25,000 square feet and smaller. For anything bigger you have to go the performance path, which they want to do because it promotes integrated design and looking at the building as a system. It adds complexity but, from our viewpoint, it adds flexibility.”
In addition, he adds, “[IgCC] has even stronger daylighting requirements than 189.1, in the sense that it requires a certain percentage of your floor space to be in a daylighted zone. Not only do you have to meet certain criteria in lighting controls and glazing, but you have to make sure you’re covering enough of your building and getting the daylight not just around the perimeter but deep into the space, and that’s certainly good for glazing.”
The new green code pushes jurisdictions that choose to adopt it beyond the minimum code level, but leaves voluntary programs such as the USGBC’s LEED rating system plenty room to push the definition of “green” into new and more demanding territory.
While IgCC tests the waters, waiting to see if localities around the country will adopt its green requirements as code, thereby making “green” mandatory, ASHRAE is moving ahead with work on its next edition of 189.1.
“They are working on stuff that we’re keeping an eye on,” Culp says of the ASHRAE 189.1 committee (see Keeping an Eye on the Next Standard Requirement on page 39).
The next version of IgCC will be issued 2015. Before development can begin, code developers will need to see what happens in the upcoming edition of the IECC; IgCC will always have to push beyond the minimums established in IECC. What the IgCC truly brings to the table is the potential for a locality to make green performance mandatory of all of its new construction. This mandatory aspect is the primary difference between the I-code and the most widely used green program, LEED.
LEED Turned Code
“USGBC’s LEED program still has a major influence on sustainable design. Even if the project never makes it to the actual certification stage, many projects are shaped by this program during the design stage,” says Mike Turner, vice president of marketing for YKK AP America Inc. in Austell, Ga., who also served as a co-chair for the American Architectural Manufacturers Association working group on IgCC.
Tony Parker, LEED AP BD+C, project manager for Walters & Wolf Curtain Wall in Mukilteo, Wash., agrees, based on what he sees in the field.
“LEED is still the primary measuring stick for designers because it allows for a real, understandable and quantifiable means of determining a building’s amount of ‘green’ design and performance,” Parker says. “LEED seems to be dominant throughout the majority of projects we see and participate in these days. Almost every project we are involved with is trying to achieve some level of LEED certification. Furthermore, the construction industry as a whole seems to be saturated with LEED-accredited individuals. That fact alone may be the single biggest indicator of LEED’s current impact on the construction industry in this market.”
Culp agrees. “LEED is clearly the most dominant green program out there, used by government and private buildings alike. It’s very popular, sometimes controversial, but it is the dominant system out there. But then you also have ASHRAE 189.1 and then you have the IgCC, and the USGBC is actually partners on both of those.
“It’s a little strange that they’re helping to develop the competition, but the main difference between the green codes and LEED is that ASHRAE 189.1 and IgCC are both written as codes and standards; they’re not point systems like LEED. While they still offer a lot of options and flexibility, they’re written in the mandatory language [of codes] rather than letting the designer choose what points they want to have,” Culp says. That language is exactly what prompted the creation of the codes. “There was pushback from some of the cities and counties and states that said ‘we want all of our public buildings to be LEED-certified’ and then people would say ‘but that’s not a code or a standard.’ Their hope is that by being written in a code format [green building codes] will be used more, especially in public, state and government buildings,” Culp says.
Parker points out that, at times, the requirements the glazing industry sets out to meet for LEED makes it all the more obvious that LEED is not a code in and of itself.
“There are times when the local energy code may be in direct conflict with LEED,” he says. “For example, LEED tends to value increased daylighting in workspaces via the glass to promote better working environments, but the overall U-value of the curtainwall may be compromised to achieve this. With all that said, it is important to note that the glass and glazing’s portion of contribution in terms of points to the overall LEED rating is rather small when compared to the many other aspects of the building design and construction process.”
Parker adds, “Remember, LEED was always intended to be a completely voluntary system. By incorporating LEED style concepts into the energy and/or building codes, ASHRAE 189.1 basically turns this voluntary system into a mandatory one. That’s a pretty significant jump, if you ask me.” However, the jump is only an issue in localities that adopt the mandatory use of that system. Without adoption of the codes, there’s no external push to promote energy performance.
IgCC’s Limited Range
“As it pertains to glass and curtainwall, I have not seen any evidence suggesting that the IgCC or ASHRAE 189.1 are currently affecting glass selection or curtainwall specified performances on the projects we are involved with,” Parker says.
“While there has been a lot of attention given to the IgCC, we have not seen much evidence of it affecting the selection of fenestration on projects to date,” Turner agrees. “From our perspective, it appears the primary driver for using advanced systems has not been code-related, but rather to simply improve the building’s thermal envelope, reduce heat loss and minimize formation of condensation. Many times, this activity is connected with performance requirements to match the function of the building, such as medical or institutional facilities.”
For states that do seem to be focusing on the IgCC in relation to full-scale commercial construction—including Maryland and Oregon—glazing contractors may not have had the opportunity to see this code in specifications yet due to the lack of projects going up in those states. Of the several glazing contractors in those states contacted for this article, the consensus was that it’s difficult to tell the impact of the IgCC requirements on new construction when there’s little new construction to report.
Among the most notable adoptees of ASHRAE 189.1 has been the U.S. Army, but even that mandatory adoption has been questioned.
“For a while it was a mandate that all army facilities, not just in the United States but worldwide, be built to ASHRAE 189.1 or at least parts of it; they would pick and choose certain chapters to follow,” Culp says. “But in one of the defense authorization acts, where they fund the defense, there was a requirement that the Department of Defense (DOD) do an analysis of all the green standards—LEED, ASHRAE 189.1, Green Globes, etc.—to see if they’re cost-effective before they actually implement that. There might be a backlash on that, and it could be good or bad. They might come back and say ‘yup, this is great, we want you to use this on every—not just Army—but every DOD building worldwide,’ or they might come back and say ‘well, it doesn’t prove out, we’re going to pull the plug and not use it at all.’
Is Green Design Really Green?
Already glass and window manufacturers are working to ensure that codes and standards adopt new requirements that, through simulation and testing, show evidence of truly improving a building.
“An important concept that our industry must work to uphold is the basis of improving codes based on data that justifies that the recommended change will, in fact, reduce the building’s energy demands,” Turner says.
ASHRAE is itself seeking to ensure that the buildings that reportedly meet its standards are living up to those expectations. The organization is exploring the idea of building commissioning to address the building’s built, versus projected, performance.
“Commissioning is viewed as an important part of a high-performance building. That’s traditionally been making sure that the HVAC systems are working, not just installed and high-efficiency but that they’re actually all working together, and that the lighting controls are working. That’s what they meant by commissioning in the old days. Now they want to address commissioning the envelope,” Culp says.
The chief factor the standard developers hope to address is the air leakage of the whole building.
“At first they had some very aggressive proposals, including one that would have required air leakage testing at every window, which would obviously have been a huge cost and liability on the glazing contractors, but they quickly realized that was unrealistic,” says Culp.
Now standard developers are considering requiring an air leakage test of the whole building, the equivalent of a blower door test done on homes, or offering an option to hire a third-party agent to inspect the air barrier. “That’s really the key thing. They want to go in and make sure the air barrier is working and it’s installed properly,” Culp says. “It affects our people, especially the glazing contractors, in that they need to pay careful attention to not just installing the window and the glazing, but how it interfaces with the wall.” This will go beyond consideration of sealants and other water management techniques to include more of a focus on incorporating glazing into the air barrier layer.
However, Culp adds, “[Commissioning] still does not get at the point of a year later or two years later, is it working the way it was designed? People are aware of that issue and so one thing they are requiring is metering. When these buildings are built (and there are certain exceptions for small buildings), they have to include metering on the building and of different parts of the building so that you can easily see how much energy is being used and where is it being used. The idea is there’s still no requirement for somebody to go back and check that, but at least it will be easier for the building owner to monitor, and if they want to go back and check how they’re performing in real life, it’s easier to do so.” In the much longer-term, ASHRAE is working to develop a building labeling program that would base green performance on real data, not just design projections.
“Their goal is that when you’re selling a space you have an idea of its energy consumption. That will affect real estate values,” Culp says. He adds, “It’s a new thing, still in its infancy, but they’re pushing that way. I know ASHRAE has been pushing that with some other big groups, trying to get federal backing for it.”
Waiting for Impact
“At this time, it is still too early to anticipate what changes may be made to the IgCC code,” Turner says. “In recent code cycles, we’ve seen the continuous tightening of the energy codes for improved energy efficiency,” he adds.
That tightening is the point of the green codes: continually pushing the envelope to stay ahead of the efficiency requirements set out in the energy codes, and to stay ahead of normal code minimums. But is the design and construction world prepared to build to tighter standards? And, more to the point, are developers ready to shell out the big bucks for a presumably higher performing investment?
“The big question, and I don’t really have a good answer, is will it be used and how widely is it going to be used? LEED clearly influences the market. Will these green codes do so? I don’t know. It’s still early,” Culp says.
The next question might be: what’s after IgCC? Although the IgCC fills a gap left open by LEED—the need for structured, mandatory language—other programs may seek to fill additional needs.
“I’m not really sure what the ‘next big thing’ in green building will be,” Parker says, “but I am rather certain that it will take a significant amount of time to be absorbed and understood, as was the case with LEED before it became so popular.”
In other words, only time will tell.
Keeping an Eye on the Next Standard Requirement
Culp points to several areas that glass industry representatives are watching. “For instance, the visible transmittance (VT) issue we were fighting over at ASHRAE 90.1 (see November 2010 USGlass, page 10), where they want to continue to push daylighting. Pacific Northwest National Lab had developed a minimum VT proposal for 90.1, and that got rejected and voted down three times. They are not giving up. They’re taking that over to 189.1, saying ‘if we can’t get it in 90.1 we’ll try it over in the green code.’ We’ll have to debate it there as well and make the same arguments, that VT is not the same as daylighting. Daylighting is very important but you have to look at the orientation of the building, the orientation and layout of the glazing, glare control, the function of the space, along with VT, all of those things. It’s not just VT alone.”
Culp continues, “The other big thing we’re watching is they’re continuing to push full life-cycle analysis, in addition to things like recycled content. I think that’s a good thing. It’s a whole picture of how the building and the materials and parts that go into it work, but it does also add some complexity.”
Megan Headley is the special projects editor for USGlass. She can be reached at firstname.lastname@example.org.