On June 30, 2026, C40 Cities gathered world-renowned architects, policymakers, and emerging leaders at the D-Hub to confront the “Architect’s Blues”, the professional tension between climate urgency, social responsibility, and market stagnation.The session moved beyond identifying the problem to showcasing how "productive friction" can drive design excellence.

Key takeaways

• Adaptive Reuse & Architectural Grafting: Rather than tearing buildings down, panelists discussed using "architectural grafting"—injecting new life and structures into existing old buildings to increase density. This approach offers a path to delivering affordable housing and people-centred cities while reducing emissions.
• From Constraint to Creativity: Participants analyzed how municipal policies, procurement, and planning frameworks can act as drivers of innovation. By embracing adaptive reuse and regenerative design, architects can navigate rising material costs and stagnating markets.
• Case Studies in Success: Projects such as the Ex Macello (Aria) project in Milan and the Porte de Montreuil project in Paris served as examples of how financial feasibility and sustainability can go hand-in-hand.

The voices

The session featured a cross-sector dialogue between C40 Cities, the Holcim Foundation, and architecture leaders, including:

• María Buhigas San José, City Architect of Barcelona.

• Lars Jensen, City Architect of Copenhagen.
• Petra Marko, CEO of the Metropolitan Institute of Bratislava and Director of TU-BA (Bratislava Architecture Centre).
• Marion Waller, Director of the Pavillon de l’Arsenal (Paris Architecture Centre).
• Kika Krista Kjærside, Head of Program, Danish Architecture Center
• Tatiana Bilbao, Founder and Principal of Tatiana Bilbao Estudio, Mexico.
• Rodia Valladares, Design Principal and Partner at Studio Gang, France.
• Kjetil Trædal Thorsen, Architect and Founding Partner of Snøhetta, Norway.
• Laura Viscovich, Executive Director of the Holcim Foundation for Sustainable Construction.
• Jacob Meyers, Holcim Foundation Fellow and Emerging ChangeMaker.
• Helene Chartier, Director of Urban Planning and Design at C40 Cities.