Embodied Carbon vs Operational Carbon: A Comprehensive Insight into Building Emissions
In the complex narrative of climate change and the built environment, two key terms have taken center stage: embodied carbon and operational carbon. These two types of carbon emissions greatly influence a building’s carbon footprint from its inception to its operation.
Understanding Embodied Carbon
Embodied carbon can be seen as the environmental footprint of construction, represented in carbon emissions. These emissions originate from the entire lifecycle of building materials, starting from the extraction of raw materials, their manufacturing and refinement, transportation, installation, and disposal of old supplies. Simply put, embodied carbon encapsulates all the carbon emissions ‘built’ into the fabric of a building.
To significantly reduce embodied carbon, the industry needs to rethink its approach to building materials. The use of carbon-intensive materials like concrete, steel, and aluminium needs to be re-evaluated. More sustainable materials like recycled aggregates, FSC certified timber, or innovative carbon-negative materials such as hempcrete or plant-based insulation can replace traditional materials. The industry also needs to embrace techniques like modular construction and off-site manufacturing, which tend to produce less embodied carbon.
Operational Carbon: The Unseen Footprint
In contrast to embodied carbon, operational carbon refers to the carbon emissions resulting from a building’s operation. Once the construction dust settles, a building begins to consume energy for various functions like heating, cooling, and lighting. The emissions from these operations constitute operational carbon.
Operational carbon is often easier to measure and has been a long-standing focus of sustainability efforts. Retrofitting existing structures and designing new buildings with energy-efficient practices help reduce operational carbon. Intelligent building systems that optimize energy consumption, the use of renewable energy, and the adoption of advanced technologies for efficient heating, cooling, and maintenance can help manage these emissions.
The Balance of Embodied Carbon and Operational Carbon
Traditionally, the focus of sustainable building design has been on reducing operational carbon. However, as buildings become more energy-efficient, the proportion of embodied carbon is increasing. It’s not uncommon for embodied carbon to represent over half of a building’s total lifecycle carbon. This shift emphasizes the need to address embodied carbon alongside operational carbon in strategies for reducing building emissions.
In response, we see the growing adoption of whole building life cycle assessments. These assessments not only spotlight potential environmental issues but also provide insights into more sustainable alternatives. Advanced tools like Tally, OneClick LCA, and Athena have become instrumental in accurately calculating both embodied and operational carbon, offering comprehensive perspectives on a building’s environmental impact.
Moving Forward: Policies and Strategies
Reducing embodied and operational carbon requires robust and low carbon procurement policies. These policies not only focus on material choices but also demand transparency from suppliers in the form of environmental product declarations (EPDs). Tools like the Embodied Carbon in Construction Calculator (EC3) can assist design teams in making informed choices.
Moreover, organizations are starting to invest in carbon offsets to balance the carbon emissions from both construction and operation of buildings. Carbon offsetting involves investing in environmental projects that absorb CO2, effectively offsetting the emissions produced elsewhere.
Both embodied carbon and operational carbon are integral parts of a building’s life cycle. It’s crucial that we continue to innovate and adopt strategies to reduce both, contributing to a more sustainable built environment.