Metal Architecture asked several industry experts about the codes, regulations and standards facing the metal architecture industry today.
MA: The International Code Council has developed a new green code titled the International Green Construction Code to promote energyefficient buildings constructed with enforceable, safe and sustainable building codes that complement LEED and other rating systems. How will this impact the metal architecture installation, costs, documentation and design?
W. Lee Shoemaker: Although the scope of the IgCC does not focus on installation techniques, various sections of the IgCC will assume proper installation and use of materials in order to achieve the required building energy efficiency as well as its intended service life. For instance, the proposed Table 505.1.1, Building Design Life Categories and Minimum Component Design Life, includes various components utilized in a building. Each of the components must be installed correctly in order to be functional for the intended design life and beyond. Various types of insulation used in roofs and walls should be installed to achieve the intended thermal transmittance of the building component or assembly noted in the code. Likewise, proper sealing methods should be employed to limit air infiltration and leakage so as to properly heat or cool a building without wasting energy.
The materials and techniques used to comply with the IgCC regulations will increase costs in the short term with the expectations that the investment will pay off in the near future during the service life of the building project.
Brad Rowe: In terms of the building envelope, and specifically for roof and wall insulation for metal buildings, the minimum performance requirements are much more stringent than the current model codes. The “traditional” installation method of compressed fiber glass insulation, and exposed purlins and girts will not come close to meeting the more stringent prescriptive insulation requirements found in the 2012
[International Energy Conservation Code] and the anticipated IgCC. Different installation methods will be demanded from the specifying designer and the installing contractor.
There has been a tremendous amount of focus and research particularly over the last five years for metal building low-density fiberglass insulation and the methods in which it is specified and installed. Various companies and industry organizations have been lining up to perform hot box testing on various assemblies trying to achieve higher installed R-values. This is an extremely positive thing for our industry; however, I am very concerned of the integrity of the samples being tested. In order to claim accurate performance results, it is crucial that the sample is tested as it is typically installed in real buildings. That would logically require clear and proper installation instructions for the contractor including practical installation methods that will not jeopardize the safety while adhering to OSHA rules and regulations. Constructing an insulation assembly in a calibrated hot box on the ground floor should mimic what is installed 20 to 40 feet up in the air on a metal building roof.
Rick Perry: My biggest concern with these green construction codes is there is no way to compare different materials for their environmental friendliness. The [Life Cycle Assessment] that is still being developed is probably the closest way of putting a performance level on a material. The problem with it is the material can be interpreted in different ways. Metal has a great story to tell because of its recyclability, its energy efficiency and how easily it is obtained from its source. Metal is going to look very good being interpreted when you can say one product material is more environmentally friendly than another material. That’s the main concern I have with all that. The enforcement of what is going to be a green construction material is going to be an issue too. All these environmental codes and regulations have a good basis for them. Saving the environment and doing what’s best for the environment while making buildings that last longer, these are all positive things. I am concerned about making the code. Because once the code is the law, it has to be enforced. To prove that your product is environmentally friendly there has got to be more testing. There will be additional cost for record keeping to show where the products came. Those records and maintaining those certifications involve additional costs.
Mark Nowak: The IgCC is an optional code at this point except in one or two small jurisdictions. We don’t expect it will be widely adopted for several years and most likely only a few states like California (or DC) may mandate it. However, it is not unlikely that the IgCC will begin to be adopted by state and federal agencies, along with ASHRAE 189.1 (ASHRAE’s version of a green building standard for commercial buildings). Thus, even if it is not mandated widely for all construction, it will have a significant impact on a large part of the industry.
Steel will do quite well in helping a building to comply with the materials requirements due to its ability to be infinitely recycled. The major items related to metal that present the largest challenges are related to acoustic and energy requirements. Each of these issues has the potential to impact the competitiveness of metal framing systems. The Steel Framing Alliance is currently developing and testing assemblies to comply with the newest energy requirements. Although there are assemblies that can pass the acoustic requirements, the trend is toward higher requirements and to expand the acoustic requirements to address noise generated outside of the building. Complying with the IgCC should not add much if any documentation requirements for metal at this point if following the prescriptive paths in the codes. As the “green” codes evolve, this may become more of an issue. There are documentation requirements associated with the performance option in the energy section of the IgCC.
Julie Ruth: I think it’s too soon to really know how ICC’s IgCC will affect the use and installation of architectural metals in commercial buildings. From the standpoint of fenestration, the IgCC contains requirements for minimum amounts of daylit area, which is beneficial to both metal-framed and nonmetal-framed fenestration.
From the standpoint of energy conservation, at the present time it appears the 2012 IgCC will require the U-factor for all fenestration in commercial buildings to be about 10 percent lower than that of the 2012 IECC. It may also do so for SHGC. The changes in fenestration U-value from the 2009 IECC to the 2012 IECC are particularly more dramatic for metalframed fenestration because the 2009 IECC had a separate category for those products which will no longer occur in the 2012 IECC.
What is clear is that these new requirements, if they begin to be adopted and enforced in any kind of widespread manner, will require a reexamination not just of building design, but of the products that are manufactured to construct buildings. We will have to look harder at the materials that are being used and ask ourselves questions like “What is the overall environmental impact of the use of this material for this particular application?”
Robert A. Zabcik: For envelope components, installation techniques will have to include enhancements that are needed to meet air barrier and thermal performance so that the installation matches the tested specimen. Outside of that, installation won’t be terribly affected. Mainly, the generation of on-site waste has to be mitigated and metal products generally ship without much waste as it is. Far more likely to be affected are things like permitting, procurement, delivery and especially project documentation.
There will certainly be some cost impact. The biggest cost impact will come from indirect sources, like third-party certification and listing costs, which can be quite expensive, and time and labor required to document projects properly. For manufacturers of envelope components, the testing and development costs to cover things like air barrier, thermal and acoustic performance requirements will have significant bottom-line impact as well.
I think documentation is where the greatest impacts occur. For example in the steel industry, manufacturers are having to track recycled (scrap) content, scrap origin, ore origin and many other things that weren’t given second thoughts prior to the green construction movement. Since steel product raw materials change hands so often on the way to the job site, it can really be challenging keeping this information traceable. As these requirements get more prevalent, companies will have to abandon manual documentation processes and integrate things like this into their Enterprise Resource Planning solutions in the longer term.
MA: Tied into the IgCC are the International Energy Conservation Code, ASHRAE 90.1 (Energy Standard for Buildings Except Low-Rise Residential Buildings) and ASHRAE 189.1 (Standard for the Design of High-Performance Green Buildings). How will this impact the metal architecture installation, costs, documentation and design?
Ruth: ASHRAE 90.1 gives requirements for the energy efficiency of buildings other than low-rise residential. ASHRAE 189.1 is for high-performance green buildings. Neither of these standards applies to low-rise residential construction.
ASHRAE 90.1 has been in existence for a long time. There are some jurisdictions that have been using it as their energy conservation code for commercial buildings for almost 20 years. It gives provisions for energy conservation, which is really only one aspect of sustainable design. ASHRAE 189.1 is more recent. It is broader in scope, and has not been as widely adopted or enforced as ASHRAE 90.1.
The main concern that AAMA has is with the number and diversity of standards that are being developed for green construction. In addition to LEED and Green Globes, we have ASHRAE 189.1 for commercial construction and ICC 700 for residential construction, and now the ICC is developing the International Green Construction Code as well. It seems likely we will have a lot of confusion in the market place as these different sets of requirements are put into effect.
Nowak: The ASHRAE 90.1 standard will have more of an immediate impact since it is recognized in the IECC as an alternative compliance path. Both the IECC and 90.1 require higher levels of insulation that will mandate exterior foam insulation on most buildings for the first time. These requirements will present challenges for the designer to make sure the wall system with foam insulation meets the NFPA 285 fire propagation test and that the fastener system for siding or other cladding is designed to carry the load when installed through a thick layer of foam insulation. Of course, the foam brings with it some extra costs that can be significant in some climate zones. As an example at the higher end, in Hawaii-where foam will be required on homes for the first time-the extra cost will approach $4,000 to $5,000 per home.
Note that foam insulation has been required in 90.1 for some time in most climate zones and similarly since 2009 in the IECC, but these codes have not been universally adopted nor enforced. The difference maker now is that it will begin to be enforced through the American Recovery and Reinvestment Act of 2009. The ARRA requires states to adopt the latest versions of the IECC (and thus the 90.1) as a condition for accepting federal funding. Further, it requires them to document 90 percent compliance with the code.
Shoemaker: It is important to note that the International Green Construction Code is an “overlay code,” which means there are underlying documents (base codes) that will govern any areas not specifically mentioned in the IgCC. Therefore, the IgCC is really a compilation of those items intended to exceed the requirements of the base codes. The two codes referenced as base codes in the IgCC are the IECC and ASHRAE Standard 90.1. Significant changes in stringency have taken place in both the IECC and ASHRAE 90.1 recently that will have an impact on the industry whether or not the IgCC is referenced.
Both the IECC and ASHRAE 90.1 are geared only toward energy savings, whereas the overlay codes such as the IGCC have the much broader scope of sustainability and environmental impacts. The 2009 and 2012 IECC, and the 2007 and 2010 editions of ASHRAE Standard 90.1 will definitely result in changes to the way construction products are specified and installed. Major changes to the amount of required roof and wall insulation for all forms of construction, not only for metal product, will mean higher upfront costs for projects. Since the major focus of both the IECC and ASHRAE 90.1 are energy savings, cost effectiveness is used as a gauge to determine appropriate levels of insulation, so the up-front costs should be recouped by building owners in a reasonable period of time.
MA: ASCE has new wind speed maps coming out showing the wind designs to be used for buildings across the United States. How will these new agency wind map codes and regulations impact the metal architecture installation, costs and design?
Gerald L. Hatch: ASCE7 10 contains a reorganization of the wind load chapter into multiple chapters. The body of knowledge was getting large enough that separating it into chapters was warranted. This reorganization will make the wind load provisions easier to follow for the designer.
Additionally the wind speed maps were also updated to be used with a 1.0 load factor for LRFD and a 0.6 load factor for ASD which brings the wind design approach more in line with that used for seismic design.
Prior to 2010, ASCE7 used one map and Importance factors for different occupancies. The importance factors in the 2010 version have been included into the maps because of the variation with location along the coast of the importance factor. This approach is considered more appropriate. The maps also reflect updated modeling procedures for hurricane prediction.
Buildings located along coastal areas prone to hurricanes will likely see an increase in building weight. Recent research has indicated that wind speeds along the coast are more in line with Exposure D. The 2010 ASCE7 changes coastal areas from Exposure C to Exposure D.
Ruth: It is important to be aware that the primary difference between the new maps and the previous maps are the method in which the design wind speeds are determined and how they are to be applied. It’s somewhat similar to going from the previous units of measurement such as miles per hour, to metric units. Even though the maps seem to be indicating higher design wind speeds, in actual practice the design wind pressures will not change in most locations.
In most locations the primary difference will simply be the dialogue that needs to occur between the code official and the designer with regards to the actual implication of the new maps, and how they are to be applied to building design.
Shoemaker: The new wind speed maps won’t directly impact installation of metal roofing or siding. The new wind speed maps actually provide a reduction in design forces (10 to 20 percent) in most of the United States (except for Central Florida); therefore costs may actually be reduced based on the lower requirements. In Central Florida, the design forces are approximately 10 percent higher with the new wind speed maps. Separate from the new maps, Exposure Category D has been reinstated for hurricane coastlines, which could increase design forces for buildings within a mile of the coast approximately 20 percent, but this would be mostly offset by the reduction in design forces from the new wind speed map.
The biggest impact on design has more to do with the possible confusion or misapplication of the new wind speed maps than with the changes to the design forces or selection of materials, members, connections, etc. There will be three maps, and the correct map must be used depending on the type of building, i.e. an essential facility like a hospital or fire station, a typical building application, or a building with low risk to human occupants like agricultural usage. Also, if one just calculates the wind loads using the new maps, he/she may be shocked that the wind loads look 40 percent higher.
