Buildings account for a large share of global carbon emissions, and the construction industry is only beginning to grapple with the full scope of the problem. In a wide-ranging interview ahead of his keynote address at the Passive House Canada conference, architect and sustainability advocate Eric Corey Freed laid out a compelling vision for how the building sector can confront the climate crisis head on. Freed serves as Sustainability Disruptor at Morrison Hershfield, blending technical expertise, systems thinking, and humor to decarbonize the built environment. For anyone entering this field, understanding the intersection of sustainable design and professional growth is essential, much like the insights in a guide on Civil Engineering Interview Questions How To Prepare And Ace Your Next Job Interview, which can help aspiring engineers position themselves for impactful careers. The conversation covered embodied carbon, innovative construction projects, and the role that Passive House standards play in the broader journey toward net zero buildings.
The Urgency of Embodied Carbon in Building Design
Freed did not mince words when asked about his current focus. Embodied carbon, he explained, has become his central obsession, and for good reason. While energy efficiency and operational carbon have long dominated sustainability conversations, the carbon embedded in building materials, manufacturing, transportation, and construction processes represents a massive and time-sensitive challenge. The concept of the time value of carbon is critical here, because emissions released today have a far greater warming impact than those postponed even a few years into the future. As Freed put it, given that the world is on fire, there is no luxury of doing anything else until the industry deals with that fire.
This urgency drives everything Freed does in his work. He travels across North America, absorbing ideas, systems, products, and solutions from a wide range of projects. His keynote draws from the most impactful lessons he has gathered over the previous six months, offering attendees curated insights that can be applied directly to their own practice. The What The Passive House Conference In October Reveals About The Movement Growth is a testament to how this community continues to evolve, drawing in professionals who recognize that traditional building methods are no longer sufficient for the scale of the challenge at hand. Freed emphasized that embodied carbon is not just a technical issue but a strategic one that demands immediate attention from architects, engineers, and developers alike.
The fundamental question Freed posed was straightforward yet profound. How does the industry cut five gigatons of carbon dioxide out of the atmosphere? The answer, he believes, lies in upgrading every building, especially existing ones, and Passive House offers a clear, best-practices roadmap for achieving that goal.
Passive House as a Practical Roadmap for Carbon Reduction
Freed described his professional role as that of a facilitator rather than a prescriptive expert. Whether he is guiding a group of suburban municipalities through climate action planning, helping a manufacturer explore carbon neutrality, or advising a developer on building better projects, his approach remains consistent: raise issues that clients may not have considered, suggest solutions, and remain open to different pathways toward the same end goal. He does not insist that every project pursue Passive House certification, but he insists that every project have a conversation about Passive House principles. According to a detailed analysis on Passive House Accelerator Why Passive House Health Comfort Resilience Performance, these principles deliver measurable benefits across health, comfort, resilience, and overall building performance, making them relevant regardless of which specific certification path a project ultimately follows.
What makes Passive House particularly powerful as a decarbonization tool is its rigorous, performance-based framework. Unlike some rating systems that allow flexibility in how credits are earned, Passive House demands measurable outcomes in terms of energy use intensity, air tightness, and thermal comfort. This clarity, Freed noted, gives project teams a concrete target to aim for, and meeting that target almost always results in drastically lower carbon emissions. He compared the approach to triage in emergency medicine, where the most impactful and cost-effective interventions must be prioritized first. Passive House provides exactly that kind of prioritization for building performance.
Innovative Projects and Carbon Neutral Construction Methods
Freed shared two compelling project examples that illustrate how embodied carbon thinking translates into real-world practice. The first involves a developer aiming to build missing middle housing in twelve cities simultaneously. Rather than pursuing traditional construction methods, the team explored prefabrication using cross-laminated timber (CLT), a material that significantly reduces upfront carbon emissions compared to steel or concrete. The CLT boxes arrive at each site nearly fully formed, stack up to five stories high, and can be adapted to different climate zones through envelope modifications. This approach addresses both the carbon footprint and the construction speed challenges that developers commonly face.
The second project takes place on a former oil field in Southern California, where the goal is to build zero carbon buildings while simultaneously restoring the contaminated land. The team is experimenting with micro-remediation techniques, using mushrooms to clean up the soil biologically. This regenerative approach is being tested at scale, with the client, a nonprofit organization, fully committed to conservation and innovation. The project represents the kind of holistic, cross-disciplinary thinking that will define the next generation of sustainable construction. The Passive House Design And Construction Lessons From The R House Project demonstrate how these principles can be applied at a residential scale, proving that high-performance building is achievable across project types and budgets.
The Challenge of Measuring Embodied Carbon Accurately
One of the most significant barriers to reducing embodied carbon is the difficulty of measuring it accurately and consistently. Freed highlighted the complexity inherent in the task: the same type of cement produced at different manufacturing plants can have vastly different carbon footprints, making it impossible to rely on averaged assumptions. Engineers on project teams often demand precision, but the available data is not always granular enough to satisfy that need. The challenge, Freed explained, is convincing technical teams that good enough data is still useful, as long as it moves the decision-making process in the right direction.
Fortunately, the industry is responding with better tools and resources. The Embodied Carbon in Construction Calculator (EC3) tool, which was set to be released publicly around the time of the interview, has already changed how project teams evaluate material choices. Books like Project Drawdown have reframed the conversation around embodied carbon and even brought attention to previously overlooked factors such as the global warming potential of refrigerants. The following table summarizes the key tools and approaches Freed highlighted during the conversation:
| Tool or Approach | Primary Function | Impact on Decarbonization |
|---|---|---|
| EC3 (Embodied Carbon in Construction Calculator) | Quantifies embodied carbon of building materials | Enables data-driven material selection and supplier comparison |
| Project Drawdown framework | Ranks climate solutions by carbon reduction potential | Reframed industry conversations around refrigerants and embodied carbon |
| Cross-laminated timber (CLT) | Mass timber alternative to steel and concrete | Reduces upfront carbon emissions in structural applications |
| Bio-remediation (mushroom-based) | Restores contaminated sites naturally | Enables construction on previously unusable land while sequestering carbon |
The industry, Freed observed, is in a moment of productive flux. Many assumptions that architects and engineers have relied on for the past fifty years are being questioned, and new tools are emerging almost daily to support more sustainable decision making. The Passive House Concept provides a foundational understanding of how these various tools and strategies fit together within a coherent framework for building performance.
Growing the Passive House Community and Expanding Access
Freed was candid about the challenges facing the Passive House movement from within. While the technical expertise within the Passive House community is extraordinary, the conferences and professional circles can feel intimidating to newcomers. Terms like blower door tests, CFM, and EUI create a language barrier that can make the field seem like an exclusive club of technocrats. Freed urged the community to be mindful of how to expand the circle, to make Passive House knowledge accessible to developers, financial professionals, and end users who may not have the technical vocabulary but whose decisions are critical to scaling adoption.
He also shared a personal reflection on how even seasoned professionals continue to learn. After hearing Ed Mazria of Architecture 2030 speak recently, Freed noted that Mazria presented his data in a new way, framing the carbon challenge as a triage situation. Not all carbon reductions need to happen at once. The key is identifying the quickest, most affordable, and most impactful actions first. That shift in perspective, Freed said, changed how he approaches his own work. The Passive House Design Principles align closely with this triage mentality, emphasizing envelope performance, thermal bridge free construction, and controlled ventilation as the highest leverage interventions available to any project team.
- Prioritize envelope improvements and air sealing first, as they deliver the largest energy and carbon savings per dollar spent.
- Select materials with low embodied carbon, using tools like EC3 to compare options from different suppliers.
- Consider prefabrication and mass timber as strategies to reduce construction waste and upfront emissions simultaneously.
- Engage building departments and inspectors early when proposing innovative materials like hempcrete or advanced bio based insulation.
- Make technical language accessible to non specialists by focusing on outcomes rather than metrics.
Freed emphasized that natural solutions should not be overlooked in the pursuit of technological innovation. Trees, he pointed out, are nature’s most effective carbon sequestration technology, backed by 3.8 billion years of research and development. Sometimes the best strategy is to build wetlands, plant trees, and let natural systems do the heavy lifting of carbon capture.
Conclusion: A Roadmap for Building Decarbonization
The interview with Eric Corey Freed makes one thing clear: the building industry has both the tools and the knowledge needed to make meaningful progress on decarbonization. Passive House provides a rigorous, performance-based framework that can guide projects toward net zero outcomes, but it must be paired with a commitment to measuring and reducing embodied carbon, exploring innovative construction methods, and expanding the community of practice beyond technical specialists. The five gigaton question, how to cut that much carbon dioxide from the air, can only be answered by upgrading the existing building stock and ensuring that new construction follows the highest possible performance standards. For professionals seeking to understand how different certification pathways compare, the guide to Green Building Certification Leed Energy Star Passive House And Net Zero Certification Programs offers a comprehensive comparison of the most widely adopted frameworks in the industry today.
The moment calls for action rather than perfection. As Freed noted, the most impactful changes are often the simplest ones done well, a well insulated envelope, thoughtful material selection, and a willingness to question long held assumptions. The time to act on embodied carbon is now, and the Passive House framework offers one of the clearest paths forward.