What is Embodied Carbon?
Despite its name, “embodied carbon” does not mean this is carbon encapsulated or contained in a material. Embodied carbon is a term used to describe the Carbon Dioxide (CO2) emissions created during the production of a material/product. This includes the energy from extracting raw materials and transporting them to a production facility, as well as the emissions from manufacturing them into a finished good.
What is Embodied Carbon in Construction?
Embodied carbon in construction includes a number of factors. “Upfront” or “upstream” emissions that are primarily related to the manufacturing of materials including the extraction of raw resources, manufacturing of building products, and the transportation of said products which makes up a large portion of what we consider to be embodied carbon. In other words – it is everything used to create the building, and what wastes are produced in the process that create carbon emissions.
Other examples of embodied carbon in construction include but are not limited to greenhouse gas emissions from demolishing a building, transporting waste to a landfill, the landfill itself, the recycling process of past material, and the methods of constructing the building itself. Overall, Embodied carbon helps to showcase a more accurate portrayal of the carbon footprint of a building over its entire lifespan – from creation to current day-to-day carbon impacts.
Is There Embodied Carbon in Construction Materials?
As mentioned above, all building products, as well as in the materials used to create the building products, have embodied carbon. An example, embodied carbon in roofing materials would include emissions related to the extraction of raw materials, manufacturing of the roofing materials and transportation of these materials to
the job site.
How is Embodied Carbon Calculated?
Embodied carbon emissions are calculated and reported through life-cycle assessments (LCA’s). LCAs are a part of Environmental Product Declarations (EPD’s), documents some construction products have available to help building owners evaluate the sustainability of a product. A cradle-to-grave EPD will determine the amount of damage to the air, land, and water created through the entire life span of a particular product whereas a cradle-to-gate EPD will only look at damage done up until the use of that product. That damage will provide you with the impact of the embodied carbon emissions in tonnes (metric tons) of CO2 through Global Warming Protentional (GWP). Assessing embodied carbon is unique for each building project and product used and it is important to look into more than this one metric as embodied carbon calculations are estimates, not absolutes. Other sustainability items to consider are recycled content, energy savings and longevity of the product if looking for a complete sustainability picture.
Is There an Embodied Carbon in Construction Calculator?
There are several calculators available online to use in determining the amount of embodied carbon being used in your construction project. Though, it is important to keep in mind that these calculators only address one area related to sustainability, embodied carbon. These calculators can be helpful in making an initial inquiry, but other sustainability items to consider are recycled content, energy savings, longevity of the product and the ability to be recycled at the end of its life if looking for a complete sustainability picture. In addition, these calculators only look at things through the “Cradle to Gate” lens versus “Cradle to Grave.” In essence, they are only measuring the impact up until the installation of the product versus what the impact of that product is over its entire life cycle. An example, embodied carbon calculators do not take into consideration the recycled content Sika’s roofing membranes have, the energy savings the white reflective roofing membrane is contributing to, the above average length of performance leading to less material headed to landfill or the old roofing membrane being diverted from the landfill all together with Sika’s end of life membrane recycling program.
How to Reduce Embodied Carbon in Construction?
Reducing embodied carbon in construction can be tackled in a number of ways. The current, high-level consumption of products has an impact on the environment, therefore the easiest way to reduce the amount of embodied carbon is to consume fewer resources or look to use products that have recycled content. Focusing on products that are more resilient and durable is another option. The longer they last, and the more extreme weather they can withstand, the longer this keeps the product out of the landfill and the less the need to consume more products.
What Other Sustainability Attributes Should Be Considered Along With Embodied Carbon in Construction?
While embodied carbon is one important aspect to consider in the overall sustainability of your construction project, there are a number of other factors that we should be considering along with it. Recycled content, longevity, energy savings, Urban Heat Island reduction, durability and the ability to be recycled at the end of its life are all important aspects in the overall environmental impact of your building.
When building your construction project, it is also important to keep in mind the resiliency of your products. By planning ahead for possible environmental stressors such as extreme wind, fire, and hail, it can seriously limit the number of repairs and replacement material needed over the life of your building. This helps to reduce product consumption and ultimately the amount of embodied carbon that could go into your building in the future.