Published on the AIA Committee on the Environment blog KnowledgeNet
By Larry Strain, FAIA
In 2006, Ed Mazria woke up the design community by pointing out that buildings were responsible for a much larger portion of GHG emissions than we had previously been aware of. The current UN Environment Report puts it at close to 40-28 percent from building operations and 11 percent from the emissions embodied in making buildings. Architecture 2030 created the 2030 Challenge that laid out a road map to get to zero emissions. In the beginning, the 2030 Challenge focused on reducing operational energy and associated GHG emissions—the AIA 2030 Commitment is about reducing the operational energy and carbon emissions of our buildings.In 2010, Architecture 2030 added the 2030 Challenge for Products, which set similar reduction goals for the embodied carbon in the materials and products we build with. This was mostly aimed at manufacturers and companies such as Interface, Central Concrete, United States Gypsum, and Owens Corning signed on.
In 2018 Architecture 2030 added another tool for reducing embodied carbon–the Carbon Smart Materials (CSM) Palette—an attribute-based guide to understanding and reducing embodied carbon in the built environment. The Palette opens with a reminder of why embodied carbon is important:
- 11% of global emissions, 28% of building sector emissions
- As buildings become more efficient, embodied emission are becoming increasingly significant.
- Embodied emissions of a building are locked in once the building is constructed and cannot be taken back or reduced.
They are also the first emissions a building is responsible for and can equal as much as 20 years worth of operating emissions. Reducing embodied emission reduces the upfront emissions from a building which is a critical step if we’re going to get to zero emissions by 2050.
The CSM Palette looks at a number of materials that are grouped into two categories:
- High Impact Materials – Concrete, Steel, Insulation and Wood
- Carbon Smart Materials – Hempcrete, Sheep’s wool, Straw and Wood. (wood is in both categories because it can have high impacts depending on how it is harvested and processed but is also is a carbon sequestering material)
The CSM Palette is great introduction to embodied carbon and how to reduce it - explanations and advice are clear and simple enough for someone unfamiliar with the topic to understand, but it’s also a good resource for those of us that have been working on this for a long time. For instance, I had never heard of the “scatter-filling aggregate” method of mixing concrete which can reduce the cement content of concrete by 20 – 30%. There are also additional resources at the end of each material page with links to papers, books and websites for those that want to take a deeper dive.
There is also a section on Whole Building Approaches with design advice for architects and engineers. It covers everything from - my personal favorite – reusing existing buildings, (significantly lower embodied carbon than building new buildings even with remodeling), to material efficiency, specifying materials manufactured with renewable energy, specifying materials that sequester carbon and a lot more.
The CSM Palette has been in development for about a year, and was launched at the Carbon Smart Building Day at the Global Climate Action Summit in September. Architecture 2030 worked with the Embodied Carbon Network, engineers, material experts and industry representatives to gather the most current information on embodied carbon and strategies and practices for reducing it.
My only real complaint is it needs more materials. The good news is there are a number of additional materials pages in development that will be coming out soon. I have been working on raising awareness on embodied carbon for the last 10 years and this is a great resource that’s only going to get better.
- Give a little guidance on what to focus on. It is helpful to understand the relative carbon impacts of the materials we build with – high volume materials like concrete and steel and high impact materials like aluminum and some foam insulations have much larger impacts than interior finish materials and batt insulation.
- Make it clear who the strategies are aimed at. Some strategies aren’t very relevant for architects and engineers and are aimed more at product manufacturers.
Larry Strain, FAIA, is a founding principal of Siegel & Strain Architects (in Emeryville, California). He has written extensively about carbon and architecture (one example is his paper, “The Time Value of Carbon”). He served as an AIA Delegate to the Global Climate Action Summit in September in San Francisco.
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