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March 2020 \ BUILDING DIALOGUE \ 23 rather an optional credit, one that many LEEDprojects contin- ue tobypass on theirway tocertificationand sustainabilityac- colades. That said, LEED certified buildings do have the poten- tial of containing lower embodied carbon as they do reward the use ofmaterialswith high level of recycled content. Most recent releases of Green Globes by Green Building Ini- tiative, IgCC (2018 International Green Construction Code) and CALGreen: (California Green Building Standards Code) now of- fer an LCA performance path alternative to prescriptive mate- rial requirements. The far less popular and pursued Living Building Challenge and Zero Carbon Certification (by International Living Future Institute) call forprojects toaccount for the total embodiedcar- bon impact from its construction through a one-time carbon offset froman approved carbon offset provider. What you can do about it. The very first question to ask is whether new construction is needed. By avoiding the use of new materials, we avoid their impacts altogether. Building reuse and incorporation of salvaged building materials can greatly reduce the embodied carbon of construction. Renova- tion and reuse projects typically save between 50% and 75% of the embodied carbon emissions compared to newconstruc- tion. “Structural systems almost always comprise the largest source of embodied carbon in the building – up to 80 percent, depending on the building type,” says Paula Melton, editorial director of BuildingGreen. Workwith your structural engineer to design lower carbon concrete mixes by using fly ash, slag, calcined clays or even lower-strength concretewhere feasible. Look for ways to achieve maximum structural efficiency. Us- ing optimum value engineering wood framing methods, effi- cient structural sections and slabs are all effective methods to maximize efficiency andminimizematerial use. Consider using high-recycled content materials. This is es- pecially important with metals. Virgin steel, for example, can have an embodied carbon footprint that is five times greater thanhigh-recycled content steel. Consider the economics – talk dollars with your clients. The best way to reduce embodied carbon is to use less stuff. And less stuff costs lessmoney. Key Takeaways 1. It’s time to pay equal attention to embodied carbon as we do to operational energy in our buildings. 2. Energy codes and most green building certifications do not enforce reductions in embodied carbon as they do oper- ational energy. 3. Similar to energy modeling tools, there are tools avail- able to account for embodied carbon of building materials. 4. Since the greatest source of embodied carbon in build- ings is from structural elements, challenge your structural engineers to minimize carbon impact of their design deci- sions. 5. Where these materials are sourced also impacts embod- ied carbon. \\ It’s All About the Carbon 303.962.9164 • cshqa.com architecture planning design We’ve Moved! Come visit us at: 2696 S Colorado Blvd Suite 525 Denver, CO 80222 Alpine Bank