Barcelona is a city of congresses. Every year, thousands of professionals arrive in the Catalan capital to debate on medicine, technology, telecommunications or research. Many of the conversations they have during these meetings end up influencing projects, companies or advances that will see the light months —and even years— later, although it is not always easy to perceive what happens inside these rooms and what impact they have outside.
This week —until Thursday, July 2— Barcelona hosts one of those congresses that, although they only last a few days, can mark debates that continue long after. More than 10,000 architects, urban planners, researchers and students from 130 countries participate in the World Congress of Architects of the International Union of Architects (UIA), the great international event of a discipline that is no longer limited to imagining new buildings, but debates how to transform, conserve and make cities more livable.
But, beyond the attendance figures and the economic impact it generates in the city, what really happens within those five days and what remains afterwards? What ideas do these 10,000 architects exchange in the plenary sessions, in the corridors or during the conversations that continue when the conferences end? Which ones will end up influencing the way cities will be transformed? And what will remain when the congress participants return home?
Barcelona is not a randomly chosen venue. It is the only city in the world that has hosted this event on two occasions and arrives at the congress at a symbolic moment, coinciding with the Gaudí Year, an architectural legacy that still defines the international image of the city. However, the current context is very different from what it was in 1996, when it hosted the congress for the first time. At that time, the city was immersed in the urban transformation after the Olympic Games.
Thirty years later, the perspective is different. The architectural debate no longer revolves solely around major urban transformations like that of the Olympic Games, nor even around how to build better, but also deals with often more invisible themes, such as, for example, how to rehabilitate existing buildings, conserve heritage, reduce environmental impact, or respond to the housing crisis. The very motto of this edition's congress —Becoming. Architectures for a Planet in Transition— summarizes this change: architecture is no longer understood solely as a finished object, but as an open and transforming process.
It is enough to walk for a few minutes through the corridors of the Barcelona International Convention Centre (CCIB), one of the epicenters of the congress, to confirm this. Several sessions are held in parallel and many fill up even before they begin. The themes range from specific issues, such as the use of materials like wood, stone, or ceramics, to broader debates on social housing or gender perspective in architecture.
The diversity of themes also attracts a great diversity of profiles —from renowned architects from countries like the United States, Mexico, or Bangladesh to local professionals or students looking to learn or create contacts— who attend the congress for various reasons. For some, it is an opportunity to learn about relevant projects and professionals, including some of the most recognized names in the international architectural scene. For others, the value lies in the conversations that arise both in and out of the plenary sessions, where informal meetings extend.
The legacy beyond the presentations
But if the reasons for attending the congress are multiple, so are the reasons why Barcelona seeks to host an event of this dimension. Beyond the immediate economic impact generated by thousands of visitors for a few days, the value lies in placing the city at the center of the international debate. During this week, anyone who wants to understand where architecture is heading has an unmissable appointment in the Catalan capital.
The sessions not only serve to understand the future of global architecture, but can also translate into local learnings. Thus, Barcelona can look, for example, to Vienna, where around 60% of the population lives in social housing, as explained by Silvia Hofer, director of Wohnfonds Wien, the public entity that coordinates the housing strategy of the Austrian capital, in one of the sessions.
The contrast with Barcelona highlights one of the great current urban challenges: in Spain, social housing barely reaches 2%, while the Catalan capital faces difficulties in increasing that percentage due to factors such as "the lack of available land or long administrative processes —which can last up to 7 years—", according to Josep Maria Borrell, director of IMPSOL, the body of the Barcelona Metropolitan Area dedicated to promoting public housing. More than copying a specific model like Vienna's, the debates serve to understand which tools have worked in other contexts and which could be adapted to Barcelona's needs.
The legacy, however, goes beyond the CCIB. It also serves to vindicate the city's architectural heritage, the only one that has hosted the World Congress of Architects twice since the UIA began organizing it in 1948. A heritage that is not limited to Gaudí's modernist postcards, but extends throughout the urban territory. Thus, the itineraries organized during the congress invite visitors to discover spaces that normally fall outside tourist circuits, from scientific institutions such as the Barcelona Biomedical Research Park to new social housing developments.
Beyond these itineraries, the congress also leaves the CCIB through exhibitions and free activities, such as the DHub exhibition, which brings together projects from the 54 member countries of the UIA. And even with initiatives that will have a physical footprint in the city, such as the competition to intervene in ten party walls in Barcelona that will transform ten walls in the ten districts of the city.
The Tres Xemeneies and the city of the future
Additionally, the congress also focuses on a space that for years has been left out of urban debate: the Tres Xemeneies of Sant Adrià de Besòs, an old industrial symbol that now faces a new stage of transformation with the aim of becoming a future large audiovisual hub. Built in the 1970s and in operation until 2011, the chimneys were for years threatened with disappearance. Neighborhood pressure allowed them to be preserved and, in 2024, the contemporary art Biennial Manifesta opened them for the first time —thanks to a major renovation— and placed them back on the city's cultural map.
Now, the World Congress of Architects becomes the second major international event to use its interior as an exhibition space, with a 4,000 square meter exhibition dedicated to thinking about the future of architecture. The exhibition, which will also open to the general public for free after the congress, allows visitors to discover an industrial interior where traces of the industrial past still coexist —with multiple posters or graffiti on the walls—.
But the Tres Xemeneies are also the setting for one of the images that will surely remain in the memory of the congress: the Open Forum, a space that every afternoon moves the debate out of the professional rooms and turns it into an open conversation facing the sea. Architects who have participated in professional sessions during the day sit in the Open Forum facing questions from attendees. This brings up issues that would hardly arise in a more technical session: "Should we preserve the sculptures of past dictators as a vestige not to forget or eliminate them to prevent them from recurring?", asks one of the attendees. "How do you rebuild a city when it has been destroyed by war?", another asks.
The answers are not always shared, but precisely therein lies the value of the debate, because when the more than 10,000 architects return to their countries and the CCIB halls are empty again, the debates of these days will continue in new projects, in other spaces and in other cities.
And perhaps when Barcelona once again hosts the World Congress of Architects —perhaps in three decades, as in this second edition— the city will be able to look back and see the physical traces of those conversations: a Tres Xemeneies transformed into a new space for events and audiovisual production, ten party walls completely transformed, and even new projects born from the connections created during the congress.