Climate change is the fundamental design problem of our time; not education, not urban sprawl, not disease, not justice. The threat climate change poses is existential, and buildings are hugely complicit—even more so than the automobile.
Buildings consume 40 percent of our energy annually, and they emit nearly half of the CO2, through greenfield development, cement production, and the burning of fossil fuels. CO2 is the chief agent of climate change, making buildings—and by association, the construction industry —profoundly responsible.
REDUCING EMBODIED CARBON
While there has been a concerted effort to reduce operational carbon emissions, that isn’t the case with embodied carbon. Reducing embodied carbon is just as important as reducing operational carbon, as the amount used to create a building can be as high as 65 percent. According to CarbonBrief (www.carbonbrief.org/mapped-worlds-largest-co2-importers-exporters), around 22 percent of global CO2 emissions come from the production of goods that are consumed in another country. While the U.S. and many European countries have reduced their carbon emissions, those reductions are offset by increasing imports that contain high levels of embodied carbon. The U.S. is the world’s largest CO2 importer, and China is by far the largest CO2 exporter, exporting five-times as much as the next country (Russia). Since 1990, the U.S. has reduced its carbon emissions by 9 percent; but according to CarbonBrief, that becomes a 17 percent increase when you factor in trade.
The COP 21 Paris Agreement sent a clear signal that the shift to a low-carbon economy is inevitable, and everyone must play their part. Our industry must do our part by taking steps to reduce embodied carbon levels when choosing building materials. To facilitate this, we must embrace meaningful action on tackling climate change from the private sector and state governments.
California has become the first state to take a major step in reducing embodied carbon emissions with the state legislature passing the Buy Clean California Act, which requires that the state set a maximum “acceptable lifecycle global warming potential” for different building materials, and specifying that only materials with embodied emissions below that level can be purchased by the state. And, since the state government is the largest purchaser of steel and concrete in California, proponents of the measure hope that it will help promote lower-carbon production practices.
This legislative act marks the first time that a U.S. state endeavored to not only reduce its emissions, but also reduce the emissions embodied in many of the materials that it purchases. As is often the case, California is taking the lead on this environmental effort. But there’s no reason that all of us in the building industry can’t follow their lead and take steps to reduce our embodied carbon emissions. Those steps include:
- Choosing materials with lower embodied carbon and sourcing materials from suppliers that are transparent in regard to the makeup of their products.
- Better design; Architecture 2030’s “The 2030 Challenge” is a great example, as it asks the global architecture and building community to meet several targets, including a fossil fuel, GHG-emitting, energy consumption performance standard of 70 percent below the local average for that building type. That 70 percent increases to 80 percent by the year 2020, 90 percent by 2025, and carbon-neutral in 2030.
- Utilizing waste and recycled materials.
- Extending the building’s life; a longer life span delays and reduces the embodied carbon associated with deconstruction, demolition, waste processing, and rebuilding.
- Increased use of prefabricated elements and off-site manufacturing.
REMAKE THE BUILT ENVIRONMENT
Our industry has the opportunity to remake the built environment so that it drastically reduces our CO2 footprint. We need to make embodied carbon count. A cubic yard of concrete (3,800 pounds) generates 350 pounds of CO2—that’s a 15 ft x 15 ft x 15 ft cube of CO2.
In 2011, the Kingspan Group embarked on its own Net-Zero Energy initiative, committing to ensure that each of its 100+ facilities worldwide are Net-Zero Energy by the year 2020, with an interim target of achieving 50 percent by 2016. Worldwide, we entered in 2017 at 57 percent renewable energy.
Kingspan believes in walking the talk. Our NZE program, simply put, is an effort to prove that energy efficiency makes commercial sense. By reducing our own energy footprint, the high-performance building products we manufacture have a lower embedded carbon footprint.
How can it be done? The Trias Energetica gives us three guiding principles.
Save more. Kingspan has the understanding and capability to create extremely thermally-efficient buildings. This expertise has been applied at every opportunity, both to improve existing constructions and to inform the design of new ones. In addition, energy efficiency saving opportunities in all aspects of our energy use are being investigated and implemented where possible.
Generate through renewable sources. A wide range of different renewable technologies have been used in different combinations, to meet the requirements of individual sites. Rooftop solar panels, solar hot water, biomass, and wind are just some of the projects that have been completed or are currently underway on our sites.
Supply any remaining demand through responsible sources. Once every avenue has been exhausted to insulate buildings, reduce demand, and generate on site, the final step in the process is to procure renewable energy to achieve 100 percent Net Zero Energy. Elsewhere, the International Renewable Energy Certificate Standard (I-REC) and alternative opportunities will be sought to track the supply of both renewable electric and green (bio) gas.
USE BEST PRACTICES
The International Energy Agency says building-related emissions are on track to double by the year 2050. Using the best practices detailed in the Trias Energetica will help our industry attack the issue of embodied carbon with the same effort that we put into carbon emissions.
About the Author:
Brent Trenga, LEED AP BD+C, is building technology director for Kingspan Insulated Panels North America. His background as an architect, construction manager, developer, and project owner give him a unique perspective on all facets of the construction industry. Trenga leads Kingspan North America’s material health and transparency program and Kingspan’s North American NZE 2020 program, while collaborating with the company’s global healthy building team. Trenga can be contacted by email at .
Modern Contractor Solutions, December 2017
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