Operational vs. Embodied Carbon: The Future of Decarbonization

In the last several decades, building professionals have updated building codes to heighten energy efficiency standards. This only goes so far to decarbonize the sector, and more regulatory action needs to be taken to address embodied carbon. 

The decarbonization of the built environment is essential for reaching carbon neutrality by 2050. The building sector emits 39% of global greenhouse gas (GHG) emissions with 28% stemming from operational carbon while the remaining 11% comes from embodied carbon. 

Home builders have been quick to adopt energy efficient standards to reduce operational carbon, but little has been done to address embodied carbon. 

Operational carbon is linked to the energy expenditure of the building. This includes carbon emitted from the use of appliances, lighting, HVAC systems, and other energy consumptive sources. Fortunately, these emissions can be improved over time with building renovations.  

Embodied carbon is the total emissions associated with extracting, mining, manufacturing, and transporting construction materials. Unlike operational carbon, emissions from material usage are a one-time occurrence. Once the material is processed, the carbon emitted cannot be improved upon. It is of the utmost importance to manufacture alternative low carbon materials to use in building construction. 

Wood, steel, concrete, and insulation are among the most commonly used construction materials that are carbon intensive.  

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The Next Step for Regulations: “Buy Clean” and Building Codes 

There is little incentive for building product manufacturers to develop and sell low carbon building materials. The market demand for sustainable materials is low and without external pressure manufacturers will continue to produce carbon intensive materials. 

Procurement policies requiring the use of alternative, low carbon materials to qualify for government contracts would remedy the lack of demand for these sustainable materials. 

A couple of U.S. states have passed procurement initiatives to mandate the use of low carbon building materials. California, New York, Washington, Colorado, and Minnesota have all passed “Buy Clean” laws that target embodied emissions. 

The governing bodies of the “Buy Clean” legislation will determine their state’s maximum Global Warming Potential (GWP) for several of the most commonly used construction materials using Environmental Product Declarations (EPDs). Currently, the “Buy Clean” laws are inactive and will not go into effect for a couple of years.  

The federal government has created the first of its kind Buy Clean Federal Taskforce to have a greater impact on reducing embodied carbon. The U.S. spends $650 billion dollars annually to fund infrastructure projects. The adoption of the “Buy Clean” initiative on the federal scale will greatly sway the market and force manufacturers into developing low carbon materials. 

For instance, the First Movers Coalition, valued at $6 trillion across 34 different corporations, has pledged to follow clean purchasing initiatives set forth by “Buy Clean” legislation. The market is already leaning towards cleaner, low carbon alternatives with the enactment of “Buy Clean” procurement policies.  

Building Codes and Embodied Carbon

Vancouver’s Zero Emissions Building Plan can be used as a case study to demonstrate the importance of embodied carbon and the role it plays in decarbonization efforts. The city is on track to reach net zero in 2025 for operational carbon and has shifted focus to embodied carbon to completely decarbonize the building sector. 

In 2030, Vancouver aims to have a 40% reduction in their embodied carbon emissions. The city’s strategy is to require buildings in the permitting process to calculate the embodied carbon. The calculation of embodied carbon early on allows builders to adapt and purchase lower carbon materials. In the next year, Vancouver will add an embodied carbon threshold to their building codes.  

The U.S. could take a similar approach to Vancouver and adopt embodied carbon reductions into the building codes. 

Carbon Software Tools and Transparency 

In the last several years, builders have created their own free and easy to use carbon software tools to calculate the embodied carbon of construction materials. Many of these carbon tools rely on Environmental Product Declarations (EPDs) to conduct a life cycle analysis of the material and determine the embodied carbon content. Mandatory reporting from manufacturers will be essential to ensure the reliability of EPDs and in turn the amount of embodied carbon. 

Builders can maximize reductions by calculating embodied carbon early in the building process. There are several carbon software tools available to builders. Gone are the days where builders rely on intuition rather than numbers to select their sustainable building materials.

Please keep an eye out for our next blog detailing the differences between each of the carbon software tools.