Five ways to reduce embodied carbon on your next building project
Climate change is the defining issue of our generation, and the building industry will play a pivotal role in leading the collective global community toward carbon emissions reduction. Carbon reduction is no longer a choice or an impossibility, it is a necessity.
According to the Intergovernmental Panel on Climate Change (IPCC) Special Report, human-induced global warming reached approximately 1°C above pre-industrial levels in 2017. If this trend continues and global temperature rise surpasses the 1.5°C mark, we can anticipate irreversible damage to our ecosystems and our overall quality of life.
The impact on my personal lifestyle is the elimination of activities like skiing or snowboarding, but for other locations around the world, it’s the difference between life, death, and survivability. The UN’s 2019 report on climate change states that in order to limit Global Warming to below 1.5°C, we need to reduce carbon dioxide (CO2) emissions by 45% by 2030 and reach net zero by 2050. This seems like a daunting task, but the alternative to not achieving these targets will be both catastrophic to our environment ecosystems as well as the global economy.
Judging economic value through the lens of shareholder value, the benefits of becoming greener are becoming clear. The rise of ESG (Environmental, Social and Governance) investing since 2005 has been significant. Today ESG investing is estimated at $20 trillion or ¼ of all professionally managed assets. 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 in 2014 55% of consumers will pay extra based on positive environmental or social impacts.
How is our industry contributing to climate change?
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 worldwide and could represent the tipping point between success and failure.
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? If we look at the final energy demand in buildings from 2017 to 2018, the demand rose by 1% and 7% from 2010. 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:
1. Operational Carbon
2. 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 flip side, the construction life cycle itself accounts for 11% of carbon emissions. The good news is that our industry is starting to move 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:
- Lower operating costs
- Increased asset value
- Providing healthier and safer environments for occupants
- Demonstrating an owner's 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, 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:
1) Measure embodied carbon emissions
Across the industry, we need to measure our embodied carbon emissions across the entire construction lifecycle.
2) 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 toward net-zero. Our current contributions and reduction targets must be publicly available to ensure we are held accountable.
3) 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.
4) 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.
5) 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 vendor and partner selection and even fund projects to put our environmental impact at the forefront.
What can I do as an asset owner?
Building owners and developers arguably have the most critical role in driving our industry towards net-zero embodied carbon. Owners can bring this issue to the forefront of the design and decision-making process by specifying:
- Only low-carbon materials to be used
- Designs that consider reducing carbon across the entire asset lifecycle
- A requirement for reducing emissions during construction activities
Owners must work with design teams to take a critical look at the designs we are selecting and focus on those prioritizing carbon reduction. For the construction phase, work with your general contractors to incentivize reducing carbon emissions and waste. Electric machinery is no longer a futuristic dream. Caterpillar, Bobcat, and Volvo, to name a few, have all introduced electric machinery in the last few years. Electric machinery not only allows for net zero, it can also have positive health and safety implications by reducing workers’ interactions with toxic emissions.
Reducing rework and waste is also a critical element, and the financial incentives here are clear. According to an ENR article, rework costs can run between 2% to 20% of a project’s total contract amount. If this isn’t a case for change, perhaps considering the environmental impacts resulting from wasted material, labor, and additional transportation may be. We need to prioritize upfront up-front planning and enhanced project and stakeholder communication to reduce the inefficiencies in our industry and pave the way toward net-zero.
Owners can and must set a roadmap to only building projects with zero embodied carbon. For existing assets, the decision to renovate versus rebuild can have crucial impacts, on top of ensuring correct operational frameworks to maximize the asset's life. Extending the operational life of a building or infrastructure asset through regular maintenance, repurposing, or renovating existing assets and ultimately reducing end-of-life emissions through recycling will allow us to become net-zero.
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 can 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.
Read more about the BIM software solutions that support sustainable construction.
* This article was originally created by Elliot Jones for E-builder, a Trimble company. Also previously published on https://constructible.trimble.com/