With the political, environmental, financial, and media attention paid to climate change, I think that we’re all pretty familiar with the role of carbon dioxide in global warming. For those of us in the Architecture, Engineering, and Construction (A/E/C) industry, we’ve been witnessing the greening of our trades since the US Green Building Council developed the Leadership in Energy & Environmental Design (LEED) designation in 1994.
And with good reason. Buildings contribute to roughly 40% of greenhouse gas emissions around the world. As such, minimizing carbon has evolved from an environmental nicety to an economic and social reality.
Carbon? Bad. Minimizing carbon? Good.
Operational vs. Embodied Carbon
But all too often, we think about a building’s carbon footprint in terms of how much carbon it emits. From that perspective, we seek ways to improve building insulation to minimize energy loss, we install air purification to make office environments healthier, and we consider ways to reflect—not absorb—sunshine to minimize air-conditioning demand.
All good practices for reducing operational carbon.
But the green movement—and by green, I mean both environmental and financial—is now shifting its attention to minimizing the amount of carbon that’s utilized in the design, construction, refurbishment, or demolition of a building. It’s reducing that embedded carbon that’s the next wave of environmental and economic efficiency.
As a project engineer working on multidisciplinary projects, I see two main paths to reduce embodied carbon: product selection and project efficiency.
Product Selection
When you’re shopping for a car, the choices can be overwhelming. New or used? Sedan or SUV? Electric, hybrid, or gas? Sunroof, moonroof, or convertible? Consumer Reports, Carfax, Edmunds, and CarGurus are a few examples of sites that allow us to surf and sort by what really matters most to us to arrive at a purchase.
Similarly, for those of us seeking to reduce the embodied carbon when designing and constructing buildings, the Embodied Carbon in Construction Calculator (EC3) is a resource worth considering. As described on its website, the EC3 is “a free database of construction Environmental Product Declarations (EPDs) and matching building impact calculator for use in design and material procurement.” Incorporated in Washington State, the EC3 is the product of a nonprofit consortium of technology, design, and construction companies attempting to reduce embodied carbon in the A/E/C industry. Its board consists of people representing such well-known companies as Microsoft, Skanska, Salesforce, Magnusson Klemencic, and Interface.
The EC3 allows designers and procurement specialists to view carbon emissions data about products available within their geographic footprint. It interfaces with Building Information Management (BIM) tools and allows contractors and subcontractors to use data to compare the carbon footprint of steel, aluminum, concrete (which combined account for almost one quarter of the global greenhouse gas emissions in the built environment), and much more to make sound business and environmental decisions. Further, EC3 also allows you to share those data with clients to help them visualize design concepts and understand product tradeoffs.
Projects that have utilized EC3 to date include the Microsoft corporate campus in Redmond, Washington; the Port of Seattle; and large-scale office developments in Los Angeles.
The tool is still in its infancy, with some 12,000 users and growing. But it’s something that allows people like me to compare and contrast product offerings to help my clients make the best long-term decisions.
That’s an important product-sourcing tool. Overall, the American Institute of Architects recommends these 10 steps for reducing embodied carbon in buildings:
- Reuse buildings instead of constructing new ones; the AIA says renovation and reuse typically save between 50% to 75% of the embodied carbon emissions compared to constructing a new building.
- Specify low-carbon concrete.
- Limit the use of carbon-intensive materials, such as aluminum and plastics.
- Choose lower-carbon alternatives: e.g., wood instead of steel.
- Use carbon-sequestering materials such as wood or straw.
- Reuse materials wherever possible.
- Use materials with a high recycled content.
- Maximize structural efficiency.
- Use fewer finish materials—intelligent design can produce an attractive yet low-carbon result.
- Minimize waste.
Project Efficiency
Being smarter with time and budget is always a goal on any project. We have ample room for improvement. A 10-year McKinsey study on labor productivity growth from 1995-2005 showed that construction generated $125 real gross value per hour worked. Sounds pretty good, right? Not when compared to manufacturing ($170/hr.) or the overall economy ($196/hr.)
When you factor in the environmental side of the ledger, project efficiency becomes even more important. Consider some everyday planning decisions we can make to make our projects more efficient:
- Consider investing and training in BIM software to improve both your interaction with clients and the efficiency of your design and construction process.
- Better phase the construction process to minimize downtime, quicken time to completion, and ensure that equipment (especially rented equipment) isn’t needlessly on site and using resources during downtime.
- Are there ways to reduce something as basic as the number of concrete mixer site trips by considering multiple ways to pour concrete instead of focusing on only that day’s task?
- Be on site. Managers don’t need to be there every day, but frequent trips to project sites can improve crew communications, underscore project importance, and illustrate that you have skin in the game along with your crew and company.
- Establish performance metrics and reward those who achieve them. At Prime, we’re big believers in transparency and metrics. That culture has fostered rapid growth and repeat client engagement.
- Especially now, focus on continually improving your procurement and supply chain management processes.
- Document and learn from previous projects. While each project has distinctive characteristics, a wide variety of processes can be standardized to increase project efficiency.
The A/E/C industry has made impressive strides to reduce the carbon footprint of our processes and projects. This new focus on reducing embodied carbon is the next logical step in making the built world healthier for everyone who calls this planet home.
I hope that these suggestions are helpful as you consider ways to reduce embodied carbon in your projects. As we all continue to learn more, I encourage you to share with me any comments, suggestions, failures, or successes you may have experienced. Contact me at [email protected].