Embodied carbon is one of the hottest topics in the sustainable building industry, and for a good reason.
51% of carbon emissions from construction will be from embodied carbon between 2020 – 2050 (Architecture 2030). Reducing embodied carbon emissions is going to be a key strategy for sustainability in the building industry.
Embodied Carbon, Explained
When many of us think of carbon emissions from buildings, the first things that come to mind are often turning on the lights, running the HVAC, or powering other things within the building. These are examples of Operational Carbon. For decades, this has been the primary focus on reducing emissions, and we’ve done a decent job at that so far. We’ve implemented energy efficiency codes, and invented more efficient systems, and alternative energy sources are fairly common.
Embodied carbon is different from operational carbon. Embodied carbon is the total carbon that comes from extracting raw materials, transporting them, manufacturing them into the final material, and transporting them to the construction site.
Lifecycle of a Product
Take a simple piece of lumber for example. The logging crew must use equipment and machinery powered by fossil fuels to cut the log. A gas or diesel vehicle drives it to a mill where electricity powers the equipment to shape the log into the desired size. Then, another gas or diesel vehicle transports it to a warehouse for storage, which operates on fossil fuels. Finally, the log is transported to the construction site for installation.
If that seems like a lot of steps to think about, imagine thinking about the same process for every single material that goes into a construction project. The amount of carbon emissions snowballs quickly, which is why it contributes to half of total emissions from buildings and construction, especially as operational energy has decreased over time.
Product manufacturers can choose to have their products evaluated for embodied carbon. This is reported in an Environmental Product Declaration (EPD). You can learn more about EPDs by viewing our previous blog post on the topic.
In our next blog, we will go more in-depth on calculating embodied carbon with EPDs. We are sticking to the basics in this blog post!
Responsibilities of Project Team Members in Reducing Embodied Carbon
When a project team decides that tracking or reducing embodied carbon is a goal, each part of the team will have responsibilities to achieve this.
Architects and Designers
Architects use embodied carbon information to make informed decisions about the materials they specify and the design choices they make in their projects.
Material Selection
Architects can choose materials with lower embodied carbon emissions. For example, they might opt for timber instead of steel or concrete. Timber generally has lower embodied carbon because of its renewable nature and lower energy requirements for processing.
Optimizing Design
Architects can design buildings with lower embodied carbon by optimizing the use of materials. This might involve designing buildings with efficient structural systems, reducing material waste, and designing for disassembly and reuse.
Life Cycle Assessment
Architects conduct life cycle assessments to quantify the embodied carbon of different building materials and design options. LCA helps architects understand the environmental impact of their design decisions throughout the entire life cycle of a building, from raw material extraction to end-of-life disposal.
Specification and Procurement
Architects can specify low-carbon materials in their project specifications and work with suppliers and contractors to ensure that these materials are used during construction.
Educating Clients and Project Stakeholders
Architects play a crucial role in educating clients and other project stakeholders about the importance of embodied carbon and advocating for sustainable design practices. By raising awareness and demonstrating the benefits of reducing embodied carbon, architects can influence decision-making and drive positive change in the industry.
General Contractors Embodied Carbon
General contractors and construction managers play a critical role in the reduction of embodied carbon and other construction carbon emissions. Here’s how they help meet embodied carbon construction requirements:
Procurement
Contractors and construction managers use embodied carbon information to procure construction materials with lower carbon footprints. They work closely with architects and suppliers to source materials that meet project requirements while minimizing environmental impact.
Embodied Carbon Tracking
General contractors and construction managers are often asked to track the embodied carbon goals of the projects, using the embodied carbon value provided by EPDs and multiplying it by the quantity of material used.
Subcontractor Coordination
Construction managers coordinate with subcontractors to ensure that low-carbon materials and construction methods are used throughout the project. They provide guidance and oversight to subcontractors to ensure compliance with sustainability goals.
Construction Practices
Contractors implement construction practices that minimize waste and energy consumption, which reduces embodied carbon emissions during the construction phase. This may include optimizing construction schedules, reducing transportation distances for materials, and implementing efficient construction techniques.
Setting Your Scope For Embodied Carbon Tracking
Anyone would be driven mad if they had to calculate the embodied carbon emissions down to the nuts and bolts holding everything together.
Instead, the project team should work together to identify the materials on the project that will contribute the most embodied carbon to the project footprint. This is usually going to include concrete, steel, aluminum, and glass. Some projects may want to only focus on concrete and steel, while others may want to account for even smaller parts of the embodied carbon footprint, like drywall, carpet, ceiling tiles, and the like.
