Are You Ready for Life Cycle Assessment?
One of the reasons working with the construction codes has held my interest for decades now is that there always seems to be a new challenge. Just about the time we start to figure something out–whether it be compliance with the Americans with Disabilities Act, three second gust or ultimate strength design wind speeds, terrorist resistant buildings, impact resistant windows or energy efficient buildings–some new challenge comes along.
The most significant of these recently, of course, is green construction. Just what does it mean to be green? Every manufacturer, it seems, wants to call their product “green” these days. At the AAMA Summer Conference, a presentation was given to provide guidance on what green claims can legally be made about a product by the manufacturer and distributors.
Just as many other groups have, AAMA has been working diligently to wrap their hands, and collective minds, around this concept for a few years now. And in partnership with what other groups are doing, it seems they may be getting a handle on it.
A New Metric for Green
As an engineer, I like to be able to quantify things. When it comes to building green, it’s all well and good to say we want to build in a sustainable manner and we want to build an earth-friendly building. But what does that really mean? If we reduce energy use, is that good for the planet? Certainly it would seem so. How about recycling materials? That also appears to be of value. Which is better for the environment–reusing an existing building that may be bigger than we really need and not very energy efficient but is close to public transportation or building a new, smaller and more energy efficient building out of recycled materials on a previously undisturbed site?
Most product manufacturers I work with want their products evaluated against their competitors on a fair and level playing field. But how is a designer to choose which product best satisfies their objective of building a green building, if one has the best thermal properties, a second has more recycled content, a third has a higher percentage of indigenous materials, and a fourth promises a longer service life than any of the others?
Is there a metric for measuring just how “green” a building is? Or just how “green” a building product is? And if so, how do we apply it? Our efforts to resolve this appears to be centering around this concept called life cycle assessment or LCA. According to people who testified at the final action hearings for the International Green Construction Code in November 2011, scientists around the world agree on how LCA is to be performed. But for those of us who have not been privy to that discussion, it’s all pretty new and still somewhat of a mystery.
LCA was mentioned in the 2008 edition of NAHB National Green Building Standard/ICC 700. A very limited number of points were available for a designer who could demonstrate that “a more environmentally preferable product or assembly” had been selected for an application based upon an LCA tool that compares “the environmental impact of building materials, assemblies or the whole building.”
In the 2008 NAHB NGBS/ICC 700, LCA is defined as “an accounting and evaluation of the environmental aspects and potential impacts of materials, products, assemblies, or buildings throughout their life–from raw material acquisition through manufacturing, construction, use, operation, demolition and disposal.” Although these provisions indicated there may be some basis of comparing product to product that goes beyond prescriptive, they did not provide much guidance with regards to how that was to be done. Nor were the incentives very high for a designer to try to take advantage of these provisions.
LCA is also addressed in the U.S. Green Building Council's LEED v.3 as an option for a limited number of points for materials and resources. At the present time, it appears that LEED v.4 will award a significantly higher number of points for third party certified LCA.
The 2012 IgCC permits whole building LCA as a project elective if the jurisdiction adopting the IgCC chooses to adopt the Appendices. The 2012 IgCC defines LCA as “a technique to evaluate the relevant energy and material consumed and environmental emissions associated with the entire life of a building, product, process, material, component, assembly, activity or service.” To qualify for the project elective in the 2012 IgCC, a designer must demonstrate that the whole building achieves at least a 20 percent improvement in environmental performance for global warming potential and at least two of the five following impact measures:
- Primary energy use
- Acidification potential
- Eutrophication potential
- Ozone depletion potential
- Smog potential
This improvement is to be made in comparison to a reference building of similar useable floor area, function and configuration. The reference building that serves as the model for comparison must meet the minimum energy requirements of the IgCC and the structural requirements of the International Building Code.
Now, I don’t really have much of an understanding of what the six impact measures are, or how they, or global warming potential, are assessed. I can look at the USGBC’s LEED website and get a brief summary of each. But that is still not going to give me the information I need to determine how it applies to a specific window manufacturer’s product. What I do know is that if a building designer chooses to use one of the LCA options provided in the 2012 IgCC, NAHB NGBS/ICC 700-08, or LEED v4.0 (once it is made available in 2013), they will need to have this type of information about your product.
Environmental Product Declaration
So a need for product information is being created here by these documents and their options. The American Architectural Manufacturers Association, together with the Insulating Glass Manufacturers Alliance, the Glass Association of North America and the Window & Door Manufacturers Association, has formed the Joint Product Category Rules Task Group to try to address this need. The JPCRTG is working with Earthsure to develop a program that will help window manufacturers provide the information described above.
The program will basically establish a protocol for developing an Environmental Product Declaration (EPD) label. The protocol will prescribe how a manufacturer is to do the following:
- Establish a list of materials in their window assemblies
- Quantify what percentage of the assembly each material is, based upon mass
- Determine the anticipated environmental impact of the extraction and transportation of each material
- Evaluate the anticipated environmental impact of the assembly of the window
- Evaluate the anticipated environmental impact of the use of the window
- Evaluate the anticipated environmental impact of the disposal of the window at the end of its service life
The proposed label will then provide the total anticipated environmental impact on specific measures. At the present time, the environmental impact measures to be listed on the products EPD label are:
- Climate change
- Respiratory Effects
- Stratopheric Ozone Depletion
- Photochemical Smog
- Land Use
The building designer could then use that information in their calculation of the environmental impact of the proposed building, to determine if it meets the criteria of the IgCC, NAHB NGBS/ICC 700, or LEED.