Reducing Embodied Carbon & Emissions in Construction
Climate change is the defining issue of our generation and the construction industry will play a pivotal role in leading the collective global community towards carbon emissions reduction. Carbon reduction is no longer a choice or an impossibility, it is a necessity.
Judging economic value under the lens of shareholder value the benefits to becoming greener are becoming clear. The rise of ESG (Environmental, Social and Governance) investing since 2005 has been significant: Total assets under management is expected to exceed $50 trillion by 2025. In addition, some studies estimate that stocks in sustainable companies significantly outperform their non-sustainable peers. This reflects a wider and growing buyer trend wherein one-third of investors find sustainability to be an important aspect of a fund.
It’s imperative to comprehensively recognize the impact humans have on climate change before we devise a roadmap towards net-zero emissions. The building and construction industry currently accounts for 39% of global carbon emissions, meaning that changes we make will have a pivotal impact across the world and could represent the tipping point between success or failure.
Over the past 50 years, the U.S. has warmed about 63% faster than the rest of the world, according to the National Climate Assessment. Climate-related disasters cause infrastructure damage, disruption of critical services, and tank property values.
Reducing Carbon Emissions in Construction
A fully decarbonized sector could reduce almost half of all carbon emissions into the atmosphere. So where do we currently stand in meeting this goal? Population growth can be attributed to a large increase in demand. And, as our global population approaches 10 billion, the international building stock is expected to double. Unless our sector changes dramatically in how it operates, this growth will consume vast amounts of natural resources and could contribute to an expected doubling of the global consumption of raw materials.
Before we dive any deeper, there are two key categories of carbon emissions we need to understand:
- Operational Carbon
- Embodied Carbon
What is Operational Carbon?
Operational carbon describes the emissions that result from keeping the building operational, such as keeping the lights on and the building cool. Operational carbon accounts for 28% of our carbon emissions. On the flipside, the construction life cycle itself accounts for 11% of carbon emissions. The good news is our industry is starting to make some movement towards lower operational impacts and green buildings. In addition, the benefits of green construction are starting to be recognized by building owners. To say the least, this trend needs to continue. Some of the benefits attributable to green buildings include (Source):
- Lower operating costs
- Increased asset value
- Providing healthier and safer environments for occupants
- Demonstrating an owners commitment to environmental stewardship and social responsibility
What is “Embodied Carbon”?
Embodied carbon is the sum of all greenhouse gas emissions (mostly carbon) resulting from the construction lifecycle of a building. This includes emissions from material extraction and transportation, the construction phase, keeping the building operational (such as refurbishment) activities, and ultimately the end of life stage through demolition and material disposal or processing.
To date, very few projects focus on reducing embodied carbon emissions or becoming net-zero. However, since 11% of carbon emissions result from these activities, this is where the construction industry needs to prioritize its efforts. Unfortunately, the impacts of embodied carbon are less understood and this article will focus on these impacts and the steps we can take to reduce our contributions.
Currently, incentives or requirements for net-zero embodied carbon are lacking but this is slowly starting to change. For instance, the Buy Clean California Act will require Environmental Product Declarations (EPDs) for certain materials being specified for state-building projects, starting on January 1st, 2020. Additionally, in 2016, the City of Vancouver published its Zero Emissions Building Plan establishing specific targets and actions for achieving zero emissions in all new buildings by 2030.
We cannot, however, wait for legislation to enforce embodied carbon reduction. We need to act as stewards of our industry and enact positive change now.
5 Steps to Reduce Embodied Carbon
The World Green Building Council has provided an in-depth report on how we as an industry can reduce our embodied carbon footprint. I have summarized five (5) of these key steps below:
Measure Embodied Carbon Emissions
Across the industry, we need to start to measure what our embodied carbon emissions are across the entire construction lifecycle.
Establish a Baseline
Once we understand the scope of our emissions we can use this as a baseline to establish reduction targets and ultimately a pathway towards netzero. Our current contributions and reduction targets must be available to the public to ensure we are held accountable.
Adopt Best Practices
Our industry will need to take actionable steps towards reduction targets. For contractors that will mean disclosure of supply chain data and material selection based on lowest embodied carbon impacts. This will require further adoption of Environmental Product Declarations (EPD) from material manufacturers to be used in the selection process.
Design With a Low Carbon Approach In Mind
Designers must take a fully integrated Life Cycle Assessment (LCA) approach to all design decisions. This approach considers not only a low carbon approach to designing but also other aspects of the project’s performance such as material, water and energy needs across the entire lifecycle.
Lead by Example
Asset owners will need to lead by example in requiring all projects to be net zero embodied carbon. This will require changing how we approach vender and partner selection and even fund projects to put our environmental impact at the forefront.
What Can I Do As a General Contractor?
The path to lowering our embodied carbon footprint will place general contractors at the forefront as they interact with stakeholders across the entire value chain. Contractors have the knowledge to influence the materials that are used, the construction processes that are employed and ultimately the carbon impact caused during the build stage. Contractors are a central hub of knowledge and influence both upstream and downstream activities and decisions.
They are responsible for informing subcontractor activities and providing embodied carbon guidelines in trade selection. In addition, contractors act as a source of quality control to help drive owner and designer decisions towards carbon neutral and reduction outcomes. According to the the World Green Business Council, contractors can:
- Minimize the carbon impact of construction processes and activities, including:
- Sourcing local materials to reduce transportation emissions
- Maximizing the efficient planning of machinery across projects and portfolios
- Sourcing plant and equipment that operates on carbon-neutral biofuels or renewable energy
- Consider installing renewable energy on-site to be used for the construction phase and then also to be transitioned to the operational stage.
- Recycle and reuse material during renovation and demolition where possible
Technology can also play a role in transitioning our business models towards embodied carbon net-zero. Building Information Model (BIM) systems can help drive efficiencies and reduce rework by informing onsite decision making. In addition, utilizing BIM in the closeout process to inform downstream operational decisions such as utility location and equipment servicing to improve how we maintain assets to increase operational life. Project Management Information Systems (PMIS) can help drive more efficient cross-collaboration and stakeholder communication as well as acting as the document depository for all EPDs. Overall, technology adoption and the transition away from paper-based workflows need to be escalated.
How We Can Help You Achieve Your Green Construction Goals
As an industry, we have limited time to achieve ambitious targets, however, the alternative is no longer something I care to consider. The future of our environment and economic success relies on the collective efforts we make now and recognition of the scale of the problem we face.
The good news is we have an opportunity to connect a net-zero strategy to the digital transformation of the construction industry. This will allow us to achieve efficiency and productivity advancements other industries have seen while also creating sustainable jobs and new markets for future generations to come.
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