Net Zero Carbon: Our Approach to Reversing Carbon in the Built Environment

In August of this year, the UN Intergovernmental Panel on Climate Change (IPCC) published the first part of its Sixth Assessment Report, Climate Change 2021: The Physical Science Basis. This Sixth Assessment reviews and synthesizes 14,000 scientific publications to provide unified information on the current state of the climate, including how it is changing, the role of human influence, and the state of knowledge about possible climate futures. Included are a number of summary statements affirming human activities are driving up global greenhouse gas emissions, warming the planet, and affecting weather and climate extremes in every region across the globe. Personally, the biggest takeaway is that many of the predicted climate change scenarios presented in the first assessment report dating back to 1990 are now being realized in 2021. One summary headline was especially disturbing and stopped me in my tracks more than anything I had come across over the 20 years this report has been assembled by the IPCC. It read, “Many changes due to past and future greenhouse gas emissions are irreversible for centuries to millennia, especially changes in the ocean, ice sheets and global sea level.” What an enormous failure. After years of predictions and cautionary narratives, the conversation has transitioned from a warning to a reality. This begs the question, “Are we as a global community able to change course, limit emissions, and avoid an increase in the frequency and intensity of changes in the climate system?” A glimmer of hope came in the headline, “Global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered. Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in carbon dioxide (CO2) and other greenhouse gas emissions occur in the coming decades.” Unless. That’s the key word. There’s the opportunity!  From a design and planning perspective, the opportunity resides in three main points of intervention summarized in the IPCC report:

1. Limit cumulative CO2 emissions starting today.
2. Reach net zero CO2 emissions by 2050 followed by varying levels of net negative CO2 emissions.
3. Reduce other greenhouse gas emissions including a strong, rapid, and sustained reduction in CH4 (methane) emissions.

Yes, this is a global problem that requires the immediate attention of every country on the planet, but we need to collectively act locally and think globally.  So, here’s how Henderson is acting locally within the design and construction industry to contribute to global sustainability efforts. In general, there are three main focal points that support sustainability and net zero design at Henderson: People, Mindset, and Process. People First, and probably most important, is making the institutional investment that supports staffing and prioritizes and promotes a culture of sustainability. Our CTO, Dustin Shafer, commented on how Henderson invests in holistically supporting the integration of sustainability, innovation, quality, and BIM into the organization saying, “Put these people on a team and set up shared goals, invest in resources to develop their ideas, and genuinely give your energy as a leader into caring about the results. Pair up passion with process.” Mindset Development and maintenance of a sustainability-focused mindset requires continuous attention and is addressed as an integral part of our quality mindset. Sustainability and net zero design is not treated as ‘nice to have’ or ‘optional,’ but rather as a definable metric in our circle of quality. Our focus on continuous improvement within this circle of quality recognizes that our mindset needs to shift from conventional ‘sustainability’ to ‘regeneration’ as described in my article on regenerative design. Process How do we approach Net Zero Carbon design and address the three imperatives from the IPCC noted above? Our engineering process involves a holistic, lifecycle approach to net zero carbon where design challenges are analyzed through the multiple lenses of sustainability, innovation, quality, and BIM to develop carbon smart, regenerative solutions. Net zero carbon buildings are achieved by addressing both embodied carbon and operational carbon. Embodied carbon, as defined by the Carbon Leadership Forum, refers to the greenhouse gas emissions arising from the manufacturing, transportation, installation, maintenance, and disposal of building materials. Operational carbon refers to greenhouse gas emissions attached to the use, operation, and maintenance of a building or project throughout its functional life. As engineers, we have the potential to make the most significant impact on operational carbon but are continually exploring opportunities within project teams to drive down embodied carbon. Whether addressing embodied or operational carbon, our net zero carbon building design approach begins with a careful site analysis followed by six key steps within the design process. The figure below is the basic sequence of our net zero carbon design framework when addressing either embodied carbon or operational carbon. NET ZERO CARBON BUILDING DESIGN APPROACH Site Analysis – Applying a regenerative mindset requires the team to establish a clear understanding of what makes a place healthy and the impacts of the local climate, existing infrastructure, natural resources, supply chain details, and characteristics of the electrical grid serving the project. OPERATIONAL CARBON Establish and Communicate Targets – Support communication within the design and construction team to establish the roles each partner plays in meeting operational carbon reduction targets. Building Electrification – Develop a systems basis of design that integrates full building electrification to provide flexibility as the grid decarbonizes and transitions to renewables. Load Reduction – Analyze energy conservation measures that reduce peak loads and even out both daily and annual load profiles. Passive Strategies – Capitalize on free site energy and resources that reduce energy required for heating, cooling, ventilation, and lighting. Efficiency – Select active heating and cooling systems that achieve optimum efficiency. Compliment efficiency with a controls strategy that helps boost overall energy and carbon reductions. On-site Renewables and Energy Storage – Design and deploy on-site renewable energy systems with energy storage to optimize how the building interacts with the electrical grid to reduce carbon emissions on an hourly basis. EMBODIED CARBON Establish and Communicate Targets – Support communication within the design and construction team to establish the roles each partner plays in meeting embodied carbon reduction targets. Design for material optimization and efficiency – Develop strategies to use fewer materials that provide identical performance. Right-size building elements and take advantage of modularization and BIM automation to eliminate waste. Analyze the supply chain – Source materials that reduce carbon emissions associated with manufacturing and transportation. Material Specifications – Write carbon smart specifications using environmental product declarations (EPDs) to assess material and energy consumption for products and equipment. Focus on key building elements like concrete, steel, aluminum, and refrigerants. Design for Durability – Select materials that can handle daily operations and last over the building’s lifespan. Plan for Reuse – Establish a plan for efficient deconstruction and reuse of key products like wood that sequesters carbon or steel that’s easily recycled. When we implement all this together with our partners, we can drive down embodied and operational carbon. So, starting today, let’s collectively do everything we can and use every tool in our toolbox. Let’s work out the kinks. Let’s keep an eye on the metrics. And let’s continuously work on the process to improve those metrics to hit our net zero carbon target.