LCAs and EPDs

As building teams work to navigate the challenging process of assessing the true sustainable attributes of building products and systems, LCAs and environmental product declarations (EPDs) are becoming indispensable tools.

Unlike a simplified, one-attribute approach to sustainability, LCAs are designed to take a much broader look at the environmental impacts produced by a product’s full life cycle. This includes the utilization of a recognized global methodology with a transparent, holistic, and balanced approach to product evaluation; an inventory of all energy/material inputs and environmental releases; the potential impacts associated with all these inputs and releases; and an interpretation of these results.

Included in this LCA is information on sourcing of raw materials, transporting the raw materials to the manufacturing plant, the manufacturing process, shipping and transportation, construction and installation, the product’s use and maintenance, and recycling, disposal, or product repurposing.

Manufacturers are then taking these comprehensive, third-party-verified LCAs and turning them into EPD labels for their products.

“The EPD provides a summary of the environmental impacts and attributes of a product that the consumer can use to gain a better understanding of a product and/or system,” explains Gary Jakubcin, president/general manager, B&G Jakubcin & Associates LLC, Pickerington, Ohio.

Along these lines, John Jewell, senior consultant, thinkstep, Boston, adds, “EPDs are communication tools that bring complex LCAs into a more user-friendly format by streamlining the information presented and enforcing as much consistency as possible.”

Putting things into perspective, Roderick Bates, LEED AP BD+C, principal, KieranTimberlake, Philadelphia, explains that for the designer, there are a lot of factors to consider when selecting a product, including cost, appearance, availability, and lead time, in addition to environmental performance. “EPDs, along with LCA software, are critical components of this selection criteria, and by making the data readily accessible, this ensures the information is available at the time material selection decisions are actually being made.”

Photo courtesy of RHEINZINK/Mark-Kempf-Photography

The University of Iowa Visual Arts Building presents an industrial aesthetic with 38,000 square feet of titanium zinc cladding and poured-in-place concrete walls. The main entrances on the southwestern and southeastern sides are covered in 1.5-millimeter perforated stainless-steel panels, thereby creating a rainscreen system.

Similarly, in an AISC continuing education unit titled “Sustainability and Structural Steel, A Closer Look,” Kevin Nasello, AIA, LEED AP BD+C, senior associate and director of sustainability, CetraRuddy, New York, states, “As architects and designers, we believe that it is our professional responsibility to minimize the impact of the structures we design and build. Analysis of the embodied energy and other environmental impacts associated with each material is an imperative first step to a sustainable building design.”

Taking a step back, the first thing that typically happens before EPDs can be developed is industry groups create a set of product category rules (PCRs). This is a standardized set of rules for the collection and reporting of environmentally relevant information within that specific product type.

Per the International Standard Organization (ISO) Standard 1402, manufacturers must use these PCRs for assembling and measuring environmental data. The PCRs are used to develop and verify the product LCA, and the full report is expert certified, signed, and posted with an EPD program operator.

“The PCR is a ‘road-map’ document that outlines how an LCA must be done and what it should include,” explains Jakubcin. “It is this process that allows a truer ‘apple-to-apple’ comparison of like products.”

In terms of why building teams are prioritizing EPDs in their projects, the American Chemistry Council in a Green Building Solutions blog titled “What is a EPD” explains:

• EPDs are becoming more available and are increasingly being used to address a growing market demand for quantified environmental information.
• The U.S. Environmental Protection Agency recognizes EPDs as a means of detailing the environmental impacts of materials in buildings.
• EPDs make decisions and judgments more informed and defensible for code officials making an approval determination.

For building products seeking green rating certifications, LEED v4 requires EPDs for some material credits and programs like WELL and the Living Building Challenge are forcing project teams to critically analyze the chemicals in the products and materials they are specifying, essentially obligating them to select healthier alternatives.

Metal Roof and Cladding LCA Research

Taking the industry’s need for detailed, transparent life-cycle product information quite seriously, a few years ago, both MCA and the Metal Building Manufacturers Association commissioned third-party experts to analyze metal building products and systems and comparable materials.

MCA’s initial study, “Life-Cycle Assessment of Metal Construction Association Production Processes, Metal Roof and Wall Panel Products,” conducted by thinkstep (previously PE International) reported that raw materials acquisition and processing were the primary variables driving the environmental profile of these products.

The main findings emerging from the study, conducted in accordance with ISO 14040/44 and 21930 standards, reported that the appropriate treatment of waste material can significantly reduce a product’s environmental profile. At the same time, upstream metal production accounts for a good percentage of the environmental footprint. Another noted finding was that transporting the goods and materials is minor within the context of the overall manufacturing process.

As for the MBMA study, Walter P. Moore and Associates was brought in to compare the environmental impacts of a metal building system to other forms of construction as calculated by Athena Institute Impact Estimator software.

The industry-accepted software were selected for its ability to model more than 1,200 structural and envelope assembly combinations, thereby enabling comparison between multiple design options.

In this case, environmental data was reported for each systems’ global warming potential, ozone depletion potential, acidification potential, smog potential, nonrenewable energy, and eutrophication potential. A total of 30 buildings from three different areas of the country were analyzed.

Ultimately, the results were quite compelling, as metal buildings showed lower environmental impacts in all six metrics when comparing structural and envelope materials to load-bearing masonry walls, concrete, tilt-up, and steel-framed construction of the same building footprint and functional equivalence. The report results concluded that for the types of building where metal buildings are typically most economical, they generally perform better in LCA analyses and produce the least embodied building material impact.

Photo courtesy of CENTRIA/Joe Brennan Phalanx Studios

To maintain the authenticity of the original Speed Art Museum in Louisville, Kentucky, three shifted volumes sheathed in fritted glass and folded aluminum panels were stacked along the 60,000-square-foot north pavilion. The design also includes an aluminum composite wall panel system, custom corrugated expanded aluminum panel system with a custom pattern, a metal wrap insulated-core metal wall system, corrugated screen wall with aluminum corrugated wall panels, and aluminum fixed louvers.

Updating the availability of this valuable life-cycle data, MCA commissioned yet another study last year, “Life Cycle Assessment of Roof and Wall Envelope Assemblies,” conducted by thinkstep and reviewed by three independent, third-party experts.

The study’s primary goals included the following:

• Understanding the magnitude of the selected potential environmental impacts per life-cycle stage.
• Understanding how assemblies based on MCA products compare to assemblies based on competitive exterior cladding products.
• Using LCA results to inform a marketing strategy to help differentiate metal products with lower environmental profiles.
• Creating a road map for MCA to continuously improve the sustainable performance of wall and roof panels.

In order to evaluate and compare roof and wall envelopes, KieranTimberlake was commissioned to design functionally equivalent roof and wall assemblies, and thinkstep evaluated the environmental performance of the assemblies for cradle-to-grave parameters, including raw materials production, component manufacturing, transport to job site, installation, maintenance and replacement, deconstruction, and disposal.

In place of EPD information, which is developed based on PCRs that contain a variety of different assumptions, MCA chose to have thinkstep develop an LCA model created with GaBi software, which provides the life-cycle inventory data for several of the raw and process materials obtained from an upstream system and offers more consistency for the materials evaluated in the study.

The life cycle for the analyzed systems was broken down into five stages:

• Product: production of materials and/or components used in each assembly
• Construction process: transport of materials to the job site and erection of the assembly at the job site
• Use: maintenance, including repainting and replacement of components, as they reach the end of their respective reference service lives
• End of life: demolition of the assembly at the end of the building service life (60 years), as well as recycling, incineration, or landfilling of the assembly materials
• Reuse/recovery/recycling potential for recycled materials

As compared to MCA’s 2012 study, this time, a total of eight inventory/impact categories were applied. To better understand the characteristics of each of the categories, the following definitions are provided.

Global warming potential is a measure of greenhouse gas emissions, such as CO₂ and methane. It is these emissions that are causing an increase in the absorption of radiation emitted by the planet, thereby exacerbating the natural greenhouse effect. It is generally assumed that this is causing adverse impacts on ecosystem health, human health, and material welfare.

The next category, eutrophication potential, focused on nitrogen and phosphorus which, in high levels, are suspected to cause an undesirable shift in species composition and elevated biomass production in both aquatic and terrestrial ecosystems.

Acidification potential is defined as the measure of emissions that cause acidifying effects to the environment. This is a molecule’s capacity to increase the hydrogen ion (H+) concentration in the presence of water, which then decreases the pH value. Potential adverse effects include fish mortality, forest decline, and building material deterioration.

In the category of smog formation potential, ozone (O₃) and other smog-related chemicals are produced when volatile organic compounds (VOCs) and carbon monoxide are exposed to nitrogen oxides under the influence of UV light. Ground-level ozone is suspected to cause harm to human health and ecosystems and may also damage crops.

The next level of suspected ozone damage, ozone depletion potential is the measure of air emissions that contribute to the depletion of the stratospheric ozone layer. The depletion of the ozone allows higher levels of UVB ultraviolet rays to penetrate the earth’s surface and cause detrimental effects on people and plants.

Abiotic resource depletion is the consumption of nonrenewable resources, which decreases the future availability of these resources.

Primary energy demand accesses the total amount of primary energy extracted from the earth, expressed in energy demand from nonrenewable resources and energy demand from renewable resources. Efficiencies in energy conversion are also taken into account.

Finally, water consumption measures the net intake and release of fresh water across the life of the product system.