The 2012 International Energy Conservation Code will go a long way to achieving the energy goals of the United States, and while some building systems and products could be severely hampered by the new code requirements, the EIFS industry should shine.
“We see very little downside and a lot to gain from it,” says Dave Johnston, executive director for the EIFS Industry Members Association, Falls Church, Va. “If there is a wall cladding that can meet the energy efficiency requirements in the IECC, it is going to be EIFS.”
The International Code Council’s IECC and the ASHRAE 90.1 (2004) will become the benchmark for the new energy legislation. A study done by the Pacific Northwest National Laboratory shows that ASHRAE 90.1 has already significantly advanced energy efficiency in the United States. “With the increased energy requirements it is going to be difficult for in-cavity insulation to keep up with EIFS,” Johnston says.
“This nation is just at the beginning of the serious debate on energy efficiency,” adds Johnston. “There are going to be a few mistakes made and maybe some of the requirements in the IECC are a bit ambitious at this time. But should we stop and not try to meet those requirements? We need to get there some day, so maybe by extending our reach, we’ll start to see an improvement.”
Published by the ICC, the IECC is effective in more than 40 states. It is updated every three years.
EIMA Research
In October, findings on EIFS performance in seven ASHRAE-established climate zones are expected to be released by Oak Ridge National Laboratory. Unfortunately, the findings won’t be delivered in time to have an effect on the upcoming IECC hearings, but Johnston believes they will build an even stronger case for exterior insulation and finish systems for the 2015 IECC. Called Phase III, the computer simulated study is assessing a number of wall assemblies for energy performance and moisture control.
The study follows 30 months of testing (Phase I and II) at the noted testing laboratory between 2005 and 2007. Over that period EIFS outperformed all other wall systems for thermal insulation and moisture control. Other systems included walls of brick, stucco, concrete block and cementitious fiber board, Johnston says.
The two-phase study was done on a building near Charleston, S.C., that featured various wall claddings and assemblies. In Phase II, a design flaw was created, allowing water to penetrate the systems. The EIFS wall configuration performed the best, while brick had the lowest thermal and moisture performance. The EIFS assembly contained a liquid-applied water-resistive barrier coating and 4 inches of expanded polystyrene insulation board. The conclusions are that the vertical ribbons of adhesive provide an effective means of drainage. No insulation was used in the wall cavity behind the EIFS assembly. EIMA and the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy’s Building Technologies Program are sponsors of the three-part testing initiative.
Green Code
On another front, EIMA was closely following the development of the International Green Construction Code when this article was being prepared, and will follow with a review of those tables in the IECC soon after.
“It’s fertile ground for one industry to eclipse another one,” Johnston says. He says there is, at present, an overlap in the requirements contained in the IGCC and the IECC.
“The ICC has to take in consideration why they need energy efficiency requirements and enhanced thermal requirements in both codes,” Johnston explains. “We are somewhat perplexed by the overlap and where it might be going.”
The ICC launched the development of the IGCC in 2009 specifically to focus on new and existing commercial building design and performance. IGCC version 1.0 was done in partnership with the American Institute of Architects, which aims for carbon neutrality by 2030. While version 1.0 is “very much a draft,” a hearing on version 2.0 could follow as early as January. The agenda calls for the completion of the draft in time for implementation in the 2012 code.
“Some people want to see the green construction code as an overlay, to fill in gaps to enhance the greenness of buildings where the other codes are silent,” adds Johnston, noting EIMA hasn’t taken a position on whether it would prefer an overlay code or a “fully stand-alone” code. “EIF systems are very much green, so they can accommodate requirements in any situation.”
A proprietary study by the National Institute of Standards and Technology that compared EIFS and other wall systems illustrated the green merits of EIFS.
Along with the AIA, ASTM International has been involved in the IGCC’s development. Eventually, the U.S. Green Building Council, the American Society of Heating, Refrigerating and Air Conditioning Engineers and the Illuminating Engineering Society joined the team in the development of Standard 189.1-2009 for the Design of High-Performance Green Buildings, Except Low-rise Residential Building.
R versus U
One important step along the way to developing new code standards is what energy performance measurement stick to use. Is R-value the right tool?
At a recent meeting of the ASHRAE 90.1 Building Envelope subcommittee, “it was agreed that R doesn’t truly reflect energy efficiency, but U (the reciprocal of R) does,” Johnston says.
U-value is the rate of the heat flow whereas R-value is the resistance to heat flow. The committee appointed a task force to draft a plan to further review the two measurements.
The U-value is a more accurate measurement of energy performance, but it could dictate new demands on wall systems, including EIFS-clad assemblies, Johnston adds.
Glazing
The glazing industry fought a hard battle earlier this year in ASHRAE’s Building Envelope subcommittee, which had recommended limiting the size of windows to 30 percent of the window-to-wall ratio. The glazing industry, however, is building a case for itself as an energy efficient system that could trump other systems when daylighting controls are a factor. Some studies show that with daylighting controls, a glazing system can outperform some opaque walls (any wall system you can’t see through is opaque) because it minimizes the use of electricity for lighting the building interior.
Whether such glazing systems become an industry standard remains to be seen, but the ASHRAE 90.1 subcommittee did vote to agree that the window-to-wall ratio could be expanded to 40 percent when there are daylighting controls. This new provision will be in the 2010 version of ASHRAE’s 90.1 Energy Standard for Buildings Except Low-rise Residential Buildings. Without daylighting controls, the maximum size of glazing remains at 30 percent.
EIMA needs to assess some of the studies done on glazing systems with daylighting, but such systems may have a while to go to catch up to performance standards that EIFS has set, suggests Johnston. “Right now EIFS are easily the pick of the litter, so to speak, in wall claddings in the opaque wall industry,” Johnston adds.
National Multi Housing Council
Proposed energy code standards are too high, say some critics who suggest amortization periods of energy efficient products and design could take five decades or longer. One of those critics is the National Multi Housing Council, which represents the country’s largest apartment building firms.
The council conducted computer simulation research on about 500 apartment buildings through eQUEST (used as a reference for the California energy code) and 500 through WUFI, a computer program for realistic calculations of heat and moisture movement in multi-layer building components exposed to natural weather. The objective was to figure out the best ways to design and construct energy efficient building envelopes.
Ron Nickson, NMHC’s vice president of building codes, says the results of the research were startling, concluding that 60-year to 200-year paybacks were likely for some of the proposed energy code criteria.
In some cases, the computer simulations concluded that entirely new methods of construction would have to be devised to meet some of the proposed energy requirements. A case in point is the recommended addition of a few inches of expanded polystyrene foam insulation on building exteriors. That would be difficult, if not impossible, to construct when using a number of cladding options such as brick, vinyl siding and cementitious fiber board. EIFS is one of the systems that would meet such a standard, but not every building can be constructed with EIFS, Nickson points out.
Steel Framing Alliance
EIFS, meanwhile, is showing up in tests put on by the Steel Framing Alliance. SFA is testing 20 different wall assemblies on cold-formed steel stud walls at Oak Ridge National Laboratory. Three of those wall assemblies were provided by EIMA with the objective of comparing the energy efficiency of in-cavity insulation to continuous exterior insulation over steel studs.
“We feel our system will do very well against other systems that are included in the tests,” Johnston says.
Many of today’s wall assemblies that are applied over steel studs haven’t been tested since the 1990s when R-11 batt insulation was common, points out Mark Nowak, president of the SFA. “We’re way beyond that now,” he says. “This will give us good information in order to comply with the new code.”
Testing includes some assemblies with warmwalls (wall assemblies built with insulation on the outside) with varying thicknesses of insulation. Some warmwalls won’t have cavity wall insulation; others will contain up insulation rated up to R-21. A maximum of 4 inches of exterior expanded foam insulation will be used in the tests, in accordance with code standards.
The analysis is expected to show how much cavity wall insulation is required in various warmwall designs. “If we are going to put enough foam insulation on the outside anyway, we believe that we might not have to put insulation in the cavity wall to comply with code,” adds Nowak. “Exterior insulation generally gives you a better installation because you don’t have all the gaps that you have with batt insulation in cavity walls.”
Initially the SFA only had enough funding to do tests on two warmwalls, but EIMA provided additional money for more warmwall testing, Nowak says. Testing should be completed in late October. The data will be delivered to officials at the ICC and the ASHRAE committee for parts 90.1 and 90.2.
Unfortunately, the results of the SFA’s initiative will be too late to be evaluated in time for the 2012 IECC—the earliest entry will be the 2015 code update. However, from the tests the SFA will publish design guidelines for architects and other key consultants, who can provide the details to building officials for review when designing new buildings. “It will be the only data of some of these assemblies in existence.”
“Another objective of the tests,” points out Nowak, “is to combine the data with other tests we’ve done to fine-tune a calculation method for cold-formed steel studs so that we don’t have to test everything every time we want to make changes.”
Don Procter is a free-lance writer in Ontario, Canada.
