Library of Reuse

What would it take to make building with reused materials as simple as building with new ones?
Andreas Oefner, managing director of Zirkular GmbH, joins Mikhael Johanes from the Chair of Circular Engineering for Architecture to discuss how circular construction depends not only on materials, but on rethinking entire processes. Drawing from his background in architectural drafting and history, he reflects on how technical knowledge and systems thinking can come together in the challenge of scaling reuse.
At the center of the conversation is Planular, the digital platform developed by Zirkular to organize material inventories, connect donor and receiving projects, and coordinate reuse — revealing that one of the biggest barriers to circular construction is not a lack of reusable materials, but the difficulty of connecting buildings, components, and people within the same process.
Episode credits
Interview byMikhael Johanes. Produced and edited by Jennifer Bartmess with assistance from Reva Saksena and Giulio Ceccarelli. Music by Coma Media. © Chair of Circular Engineering for Architecture at ETH Zurich

Product passports are a helpful tool for preserving the identities of building materials and meeting sustainability requirements. But voluntary product passports have unique advantages beyond legal requirements and audits.
Pedro Mêda a civil engineer who works at the Institute for Sustainable Construction and is an invited assistant professor and researcher at the University of Porto, joins Kasimir Forth and Silvia Vangelova from the Chair of Circular Engineering for Architecture to explore how digital building logbooks and digital product passports could reshape circular construction.
Drawing from two decades of work in academia, policy, and industry, he discusses tensions between technological innovation and industry adoption. He demonstrates how circularity requires changing how the construction sector thinks about responsibility, continuity, and collaboration.
Episode credits
Interview byKasimir Forth and Silvia Vangelova. Produced and edited by Jennifer Bartmess with assistance from Reva Saksena and Giulio Ceccarelli. © Chair of Circular Engineering for Architecture at ETH Zurich

How can technology help us better understand the built environment? Fiona Collins, Artificial Intelligence Research Engineer at Hexagon, joins Ioanna Mitropoulou, postdoctoral researcher at the Chair of Circular Engineering for Architecture at ETH Zurich, to explore how reality capture, point clouds, and artificial intelligence are reshaping the relationship between the physical and digital worlds. Starting from her background in environmental engineering and sustainability, Collins reflects on how the built environment became the focus of her work — and why bridging the gap between digital models and real-world conditions remains one of the field’s biggest challenges.
The conversation explores how data-driven workflows can support better decision-making across the lifecycle of buildings. Together, they discuss the growing role of AI in processing complex 3D data, the challenges of scaling these technologies in practice, and the evolving relationship between human judgment and machine reasoning in the built environment.
Episode credits
Interview by Ioanna Mitropolou. Produced and edited by Jennifer Bartmess with assistance from Reva Saksena and Giulio Ceccarelli. © Chair of Circular Engineering for Architecture at ETH Zurich

Computer vision is reshaping the way we understand the environment around us. Konrad Schindler, professor of Photogrammetry and Remote Sensing at Department of Civil, Environmental and Geomatic Engineering at ETH Zurich, joins Ana Bendiek-Laranjo and Deepika Raghu at the Chair of Circular Engineering for Architecture to discuss how remote sensing and photogrammetry are transforming the way we map, analyze, and interpret the world around us.
From the blurred boundaries between photogrammetry and computer vision to the realities of working with imperfect data, he reflects on both the possibilities and limitations of data-driven approaches. He also differentiates between research and practical applications, and addresses the challenges of putting the growing amount of digital image data to good use.
Episode credits
Interview by Ana Bendiek-Laranjo and Deepika Raghu. Produced and edited by Jennifer Bartmess with assistance from Reva Saksena and Giulio Ceccarelli. © Chair of Circular Engineering for Architecture at ETH Zurich

Determining the sustainability of circularity and reuse is not easy to do. Life cycle sustainability assessment offers a way for evaluating environmental, economic and social impact. Marzia Traverso, head of the Institute of Sustainability in Civil Engineering at RWTH Aachen, discusses the complexity of quantifying tradeoffs, standardizing frameworks, and finding consensus for circularity in practice.
She talks with Heidi Silvennoinen, a PhD student at the CEA Lab and Block Research Group at ETH Zurich, and Catherine De Wolf about adapting life cycle assessment so that it can better incorporate and anticipate the sustainability and reuse of materials and components.
Episode credits
Interview by Heidi Silvennoinen and Catherine De Wolf. Produced and edited by Jennifer Bartmess with assistance from Noah Pasqualini. Music by Coma Media. © Chair of Circular Engineering for Architecture at ETH Zurich