Carbon: The New Sustainability Metric

The following post was provided by Bala Consulting Engineers.

The building industry is transitioning from measuring a building’s “sustainability” based on its energy efficiency and energy use to a more comprehensive model that includes both the operational and embodied carbon from the building. Carbon has emerged as the new sustainability metric and is here to stay.

Often when the term ‘carbon’ is used, it is a general term for greenhouse gas (GHG) emissions derived from the use of fossil fuels. With the building sector producing 39% of the total greenhouse gas emissions over the course of a year globally, the built environment has an immense impact on our climate future. Furthermore, building practitioners have an equally large opportunity in reducing this impact.

To effectively reduce emissions the best place to start is to measure. “You can’t manage what you don’t measure” as they say, thus carbon accounting practices are the best place to begin. There are two major carbon accounting frameworks– the Greenhouse Gas Protocol and Whole Building Life Cycle Assessment (WBLCA). The Greenhouse Gas Protocol aligns with ESG reporting methods, which many companies, outside of the building industry, are familiar with, while the WBLCA tool is specific to and growing in popularity across the built environment.

Greenhouse Gas Protocol

The Greenhouse Gas Protocol is a widely used framework for companies with a portfolio of buildings. Corporations are being asked by their stakeholders and even now by the SEC (Securities and Exchange Commission) to be transparent and consistent with carbon emissions reporting.  There are of course other ways in which companies can reduce total carbon emissions, however much of the work can be accomplished in built spaces through effective choices, strategies, and solutions from the design community. Building design has immediate and direct influence over scope 1 and 2 emissions through the design of efficient systems, HVAC systems, and fuel choices. Building practitioners can also influence building occupants’ choices, by designing on-site electric vehicle charging, which eliminates emissions from scope 1 and 3.

Whole Building Life Cycle Assessment

A Whole Building Life Cycle Assessment (WBLCA) digs into the stages of a building’s life, starting from raw material extraction through manufacturing of products, construction, occupancy, all the way to the demolition and disposal of the building’s materials. Considering the full life of a building is critical for net zero design and leads to better project and carbon outcomes.

Reducing operational carbon via energy-efficient design has been the focus of the building industry for years. It has often been thought of as a solely HVAC issue with MEP firms taking the lead in energy reduction strategies. However, as we start to view our built spaces more like the mini-ecosystems they are, we must recognize how all aspects of a design influence and modify other parts of the design. Energy efficiency, as with carbon, starts at the building’s conception with the site planning, orientation, and design of the façade and envelope and is continued with proper construction, commissioning, and operation. These design aspects directly influence the engineered internal systems which use energy and ultimately produce carbon that we are trying to mitigate.

Embodied carbon is the carbon emitted from the full life of the materials used in a building–starting at extraction and extending all the way through disposal. With such a vast lifecycle, material selection and management require collaboration and communication from parties during each stage of this cycle to best reduce carbon. Architects, owners, engineers, contractors, manufacturers, and more all have their part to play in this process.

Bala Consulting Engineers is increasingly seeing clients asking to measure carbon for their building designs, following either the Whole Building Life Cycle Assessment Approach or the Greenhouse Gas Protocol. An understanding of what to measure and the frameworks for doing so empowers the design community and our clients toward meaningful carbon reduction and positive action. When we get a handle on measurement, we can more effectively start to reduce emissions.