Launched in 2006, and administered by the International Living Future Institute (ILFI), the Living Building Challenge (LBC) is widely considered the world’s most rigorous green building standard. The program is so difficult that as of May 2018, there are 21 buildings in the world that have achieved LBC Certification.
A look at how metal building systems fit into the green building standard
Looking at the projects that have achieved Living Building status, you will see a lot of metal products—metal wall panels, metal roofs, curtainwalls, louvers, sunscreens and more. Most even use some type of steel framing. But what we haven’t seen a lot of is the use of a pre-engineered metal building as the structural frame.
Pre-engineered metal buildings are sustainable and energy-efficient products. They are long-lasting, durable products that offer long spans and many design opportunities. Pre-engineered metal buildings contain recycled content, and the ability to be reused and recycled at the end of its life.
Alan Scott, FAIA, LEED Fellow, LEED AP BD+C, O+M, CEM, WELL AP, EcoDistricts AP, senior associate, built ecology at WSP USA, Portland, Ore., notes that there is nothing inherent in pre-engineered metal buildings that would prevent them from achieving LBC certification, with the exception perhaps of the Materials Petal. “Generally, the early adaptors of the LBC have been organizations doing smaller, custom-designed buildings with an aesthetic preference to highlight natural materials like wood, but that is a choice and not a requirement,” he says.
To become a certified Living Building, projects must meet 20 imperatives within seven performance areas, known as Petals: Place, Energy, Water, Materials, Health & Happiness, Equity and Beauty. The Imperatives are performance based, and position the ideal outcome as an indicator of success.
Scott doesn’t believe that achievement of the Imperatives within most of the LBC Petals would be influenced one way or the other by using a pre-engineered metal building system. However, “The climate zone and energy use profile of a specific project may necessitate creating a high-performance thermal envelope in order to meet the net positive energy requirements of the Energy Petal,” he says. “In this case, the metal building enclosure would likely need to include thermal breaks to prevent heat transfer.”
That being said, one of the biggest challenges with the LBC is the material requirement. The program focuses on transparency, and a product’s impact on the environment and human health. Within the Material Petal is the Red List of 22 classes of banned toxic and bioaccumulative substances, many of which can be found in building materials.
The Materials Petal
For all metal products—framing, wall/roof panels, louvers, etc.—the biggest issue is figuring out how they fit within the Materials Petal, which is intended to create a materials economy that is nontoxic, ecologically restorative, transparent and socially equitable.
The imperatives within the Materials Petal—Red List, Embodied Carbon Footprint, Responsible Industry, Living Economy Sourcing and Net Positive Waste—aim to remove the worst-known offending materials and practices with an effort to drive business toward a truly responsible materials economy.
Ideally, the LBC envisions a future where all materials in the built environment are regenerative and have no negative impact on human and ecosystem health. Since achieving the ideal is impossible, the Materials Petal aims for transparency, where consumers are able to make truly informed decisions about the products they use and the impacts those products have on them and the world around them.
Greg Mella, FAIA, LEED AP BD+C, vice president and director of sustainable design at SmithGroup (formerly SmithGroupJJR), Washington, D.C., says, “As a natural material, it’s relatively easy to document that it meets the Red List, especially if its materials ingredients are kept simple, such as 100 percent zinc or 100 percent steel.”
Mella goes on to say that sourcing is also challenging. “LBC requires teams to provide products that are extracted and manufactured within tight radii of a project site,” he explains. “For Brock [Environmental Center, Virginia Beach, Va.,] we found a zinc product whose coil was made in the Southeast, as well as the forming of the shingles.”
Chris Hellstern, AIA, LFA, LEED AP BD+C, CDT, Living Building Challenge services director at The Miller Hull Partnership LLP, Seattle, notes that in terms of sourcing, the closer the location to the site for final assembly is preferred since the location materials come from is based on dollar amount.
The Red List
Projects going for LBC certification are not allowed to have any products that contain materials or chemicals that are on the Red List. These materials include bisphenol A (BPA), cadmium, chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), chloroprene (neoprene), lead, mercury, volatile organic compounds (VOCs) and more.
For metal building systems to be regularly commissioned for LBC projects, manufacturers are going to have to go through the Red List and make sure none of the steel they use contains any of the banned chemicals. “In terms of Red List, the primary concern would be coatings and if there is any spray-applied or already adhered insulation that would be part of a metal wall assembly, if they have that for a particular metal building,” Hellstern explains. “The metal is likely not an issue and only needs mill certificates for documentation. Coatings are more complicated, but what we are using right now is a Red List-free coating from [Minneapolis-based] Valspar Corp. [now Sherwin-Williams Coil and Extrusion Coatings] called Fluropon.”
The new, state-of-the-art Alexander Valley Winery in Healdsburg, Calif., is the second flagship of the Oakville, Calif.-based Silver Oak Cellars. In addition to being the second LEED Platinum certified winery, the project is going for LBC certification. The project team went through and carefully vetted more than 3,000 building materials and equipment choices for Red List chemicals.
Haley Duncan, LEED AP BD+C, project manager at Silver Oak, notes that a metal building system from Metallic Building Co., Houston, is used as the main structural framing component for the winery and offices, while the roof and walls are structural insulated panels that were specifically formulated to meet LBC Red List requirements.
Dave Lindstrom, senior project manager at Napa, Calif.-based Cello & Maudru Construction Co., the general contractor on the project, says they chose a pre-engineered metal building system for cost and scheduling reasons. And, “The ability to accomplish long spans as the majority of the space is dedicated to wine production so a metal building makes sense,” he says.
To aid in the challenge of finding acceptable building materials, the IILFI introduced Declare, an ingredient label for building products. The Declare label is a transparency platform and product database designed to show consumers what products they can trust. It answers the questions of where a product comes from, what is it made of, and where does it go at the end of its life?
Additional Material Imperatives
Once a metal building system passes the Red List challenge, it still has to achieve the remaining imperatives of the Material Petal: Embodied Carbon Footprint, Responsible Industry, Living Economy Sourcing and Net Positive Waste.
Scott says that he doesn’t believe there is any requirement in the Materials Petal that would preclude metal buildings. But, “if the manufacturers of metal building systems are not able to address Red List material exclusions and support the Responsible Industry and Living Economy Sourcing requirements, this may preclude a project from achieving the Petal.”
“This presents an opportunity for the industry or individual companies to demonstrate environmental leadership or to differentiate their products,” he adds. “And, many of the projects that are applying for LBC are seeking Petal Certification, meaning they earn a selection of at least three of the Petals, rather than all of them. Metal buildings are just as capable of that distinction as any other type of construction.”
Overall, there are many benefits for architects and designers to use metal building systems in their everyday projects. While manufacturers may have to figure out all of the logistics of the Red List and the rest of the Materials Petal, there shouldn’t really be anything standing in the way of having pre-engineered metal buildings as an acceptable building material for LBC projects.
“Materials are about half the solution toward achieving net zero energy buildings,” Mella says. “Materials should have good thermal properties and high-performance efficiencies. The other half of the solution is the actual form, orientation, fenestration and massing of the building.”