Rules for Better City-Making

UIA 2026 Barcelona

World Congress of Architects UIA 2026 Barcelona

Marion Waller, Director of the Pavillon de l'Arsenal in Paris, at the UIA World Congress of Architects in Barcelona.

At the UIA World Congress of Architects in Barcelona, a session convened by C40 Cities with the Holcim Foundation took on the “Architect's Blues” — the tension between the profession's climate ambitions and the market realities shaping them.

Last updated: August 25, 2026 Barcelona, Spain

From a stage shared by city architects, practice leaders, and cultural institutions, five voices offered five ways forward for making the most of what already exists in the urban fabric.

World Congress of Architects UIA 2026 Barcelona

Panel discussion at UIA 2026 Barcelona: Kjetil Trædal Thorsen (Snøhetta), Kika Krista Kjærside (Danish Architecture Center), Marion Waller (Pavillon de l'Arsenal), Tatiana Bilbao (Tatiana Bilbao Estudio), and Hélène Chartier (C40 Cities).

World Congress of Architects UIA 2026 Barcelona

Kjetil Trædal Thorsen, Founding Partner of Snøhetta, speaking on stage at UIA 2026 Barcelona.

World Congress of Architects UIA 2026 Barcelona

Tatiana Bilbao, Founder and Principal of Tatiana Bilbao Estudio, on stage at UIA 2026 Barcelona.

World Congress of Architects UIA 2026 Barcelona

María Buhigas San José, Chief Architect of Barcelona City Council, addressing the audience from the podium at UIA 2026 Barcelona.

1

Treat the existing city as your site

“The city is already there. That's my playground. It's not a blank page,” says María Buhigas San José, Chief Architect, Barcelona City Council. Her team mapped the city and found buildings occupy just a quarter of its fabric — unlocking 100 hectares of overlooked leftover space now becoming pocket gardens and shaded playgrounds.

2

Make urbanism legible

“It's our role to make architecture more democratic,” says Marion Waller, Director of the Pavillon de l'Arsenal in Paris. Citizens should be taught to better understand the built environment - where materials come from and where their tax money goes in forming a better urban realm.

3

Think first, build second

“It's a lot cheaper to do good thinking than to build badly,” says Kjetil Trædal Thorsen, Founding Partner of Snøhetta. The Norwegian architect calls for the profession to be practically minded - and think about positive positions worth defending — he borrows his own view from the poet Salena Godden: pessimism is for lightweights.

4

Learn the language of money

“If you want to change the business, you have to understand it,” says Kika Krista Kjærside, Head of Program at the Danish Architecture Center, whose program brings young architects together with engineers, constructors, and financiers early in their careers — building the shared city-making language that turns good intentions into better built outcomes.

5

Choose your battles before they choose you

“To be an activist architect, start by choosing the projects you do and the ones you don't do,” says Tatiana Bilbao, Founder and Principal of Tatiana Bilbao Estudio. For the Mexican architect, architecture is a primary form of care — and her meaningful agenda is set the moment a commission is accepted, at every meeting that follows.

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