At this year’s Belgian Pavilion in Venice, four teams of architectural practitioners were invited to rethink and riff on the experimental environment proposed by its main curators, landscape architect Bas Smets and biologist Stefano Mancuso. In this conversation, these teams describe their specific contributions and interrogations displayed within Building Biospheres at the 2025 Venice Architecture Biennale.

Listen to a conversation with curators Bas Smets and Stefano Mancuso, as part of our podcast Talks at the Venice Biennale.

FEDERICA ZAMBELETTI / KOOZ Let me start by asking how you define natural intelligence, the very notion of biosphere, and how these two understandings were translated into your reciprocal proposals for Building Biospheres.

VINH LINH / ELMĒS I can give it a try. I think natural intelligence was a starting point for Bas Smets and Stefano Mancuso, in terms of plants and the way they function to induce internal environments in the built context. From that initiative, they looked at the possibility of working with sensors and technology to adjust and adapt the interior space within our built environment, therefore ‘building biospheres’.

THOMAS MERTENS / ELMĒS Beyond the definition of natural intelligence, what struck us the most was this hypothetical notion — and the notion of this hypothetical technology, created in laboratory conditions — which they now want to bring into the real world, a new reality. The courage to take the risk of putting natural intelligence in confrontation with the real world — that's what struck us the most. That's also something that we try to introduce in our project, bringing forth new kinds of unknowns, placing these in the real world, testing and being able to understand what are the consequences of this or that technology. Does it work? Does it not work? That was one of the notions that also gave us the enthusiasm to participate.

STEVEN SCHENK I would add that what was fascinating for us was a certain logic of how things were brought together — plants or human beings, animals, given physical conditions — that a natural intelligence somehow speaks to the wholeness of things. For example, we were quite curious to see if these plants and their behaviour gain a much more subjective character, which actually shows their relationship to their context. We thought it's also interesting to understand this responsiveness in the sense of how we relate to things. For example, if you are too cold, you shiver before you put on a coat. So there is some kind of truth in responding towards your surroundings, which we wanted to discover: whether we could understand better how to relate to the pavilion, and to one's surroundings, how to establish your relationship with it. There are many secrets to be revealed and the pavilion is explicitly an expression of these, I would say. This was a fascination we had; not to see architecture as an object with properties, but more like a medium to which one relates towards.

MAUD GERARD GOOSSENSOur project follows a similar line, in a way: on this notion that plants take action and that they also react to their surroundings, just like we do. There is also this notion that they act — that their intelligence is confirmed by the ability to act — in favour of themselves. Perhaps for too long, we have been seeing plants as things that act for us, as servants for humans. Now, we should understand that these actions are driven by evolutionary benefits for themselves. If we bring them into indoor spaces, how do they react with us and their environment, how would we react to them? For us, that was the starting point: to think about how this intelligence could help us rethink the connection between plants, humans and architecture.

KOOZ It's interesting to think about architecture as a medium to which one relates. To what extent is this medium passive or active, in its relationship to humans and to the world?

STEFAAN JAMAER / PANTAThe pavilion becomes the regulating device to create an optimal climate in collaboration with plants. The Belgian pavilion is a relatively small building, equipped with an operable skylight and an irrigation system. What we tried to do is keep quite close to that Bas Smets’ idea, to use the building as a testing ground; then, to go beyond it and try the techniquein a large building. In the case of the collective housing tower, we proposed to also introduce operable windows across the entire floor of the biospheres. The irrigation in the case of our project comes from an underground natural stream. This approach sits somewhere between techno-optimism and anti-technology: plants are not technological in themselves, but they can become part of a technological system when integrated into environmental devices: the plant becomes technology, because it is connected to these devices which determine their environment. This technological hybrid is central to the idea of the Belgian Pavilion.

KOOZ Thank you, Stefaan, for that link between your proposal and the idea of the prototype. I was wondering if the others could also expand upon how you took up the project of Bas and Stefano Mancuso, on this idea of living prototypes within the pavilion as the premise for a series of broader speculations.

MAUD GERARD GOOSSENSIt started with analysing what the prototype wanted to do and what it was aiming for. In the beginning we saw it as a big heating, ventilation and air conditioning (HVAC ) system that creates an indoor climate. This made us wonder how we can redefine our comfort requirements and rethink the relationship between humans and architecture. With our project, we tried to expand and add nuance to the prototype by creating different climate rooms, because we wanted to implement micro-ecosystems; plants of different climate zones for diverse levels of indoor comfort and different human activities.

Analysing the prototype of the pavilion and the climate that it makes — which is subtropical — we looked at what kinds of human use and architectural programme fits within it. We started with that, but then we realised that we first had to understand what is comfort? We have comfort regulations for human beings, but what is comfort for plants or for a building? We looked at comfort on five levels, including temperature, air quality, humidity, light and acoustics. We made a big diagram out of it and we see it as a toolkit to start designing interspaces where plants, humans and architecture come together. From that toolkit we designed the three climate rooms that we showed in collages, displaying one possible outcome.

We propose this as a toolkit because it depends how you put together the requirement; for us, it resulted in a room with a subtropical climate that is suitable for showering and cooking, because it's so humid. We also made a more Mediterranean climate with specific dimensions and material use, which is more suitable for sitting, eating and general activities, and another room with an arid climate, that would be more suitable for rest and sleep. In our proposal, we visualised these as three separate rooms, but we imagine that these rooms can interact with each other; that would be a further elaboration. The exhibition was a way to visualise where we are now, but it's not a complete or finite proposal.

KOOZ Much of the time, standards are organised according to certain paradigms. One is given a certain parameter — for instance, office spaces should maintain one temperature, while residential should have another. Your proposal shifts the paradigm by defining thermal comfort according to activities, rather than typologies, right?

MAUD GERARD GOOSSENS & HENRI UIJTTERHAEGEN Yes, that's what we did. There are rules, as you say, for different spaces; then there are different activities that take place within these spaces. We wanted to question our comfort standards via natural climates and plants, by thinking about spaces as climates instead of functions. That’s why we have a humid room, a warm room and a really calm, dry room — it really depends on the activities as to what sort of climate is suitable. In doing so, we tried to implement more complex factors beyond what is covered in common regulations — such as how due to human activity, walking rather than sitting can increase the potential viral load released into the air. Raising carbon dioxide levels can impact indoor air quality. Today, regulations are more one-dimensional, while we have tried to make our considerations more dynamic; plants bring something to that dynamic, responding differently whether it's day or night, sunny or cloudy and so on.

That’s why we propose the use of hemp lime that could deal, for example, with the one problem that would occur if you put a lot of plants within a building, which is a condition of very high humidity. We were thinking not only about the wall, but also the inclination of the whole building: you can call it natural intelligence, but it also includes physical conditions. For instance, gravity: you can use gravity to control the way water flows. If there’s an incline, you can collect rain and water the plants within the building; at the same time, you could use shower water to heat up the building. So that's an example of how we were thinking about the building itself as an active agent.

STEVEN SCHENK What is curious is that this wall is also fire resistant; it also has a U-value that fulfills building codes. Somehow this method of building is almost like baking bread, or cookies. You have to weigh properties against each other; something might insulate or store heat, but it might not do everything as well as the best-performing material in its class. But in the end, like this, there are these nuanced materials that perform more actively together. In this sense, they may not be defining an inside or an outside; it's more about offering conditions. Maybe that's maybe the thing we liked more about this approach.

KOOZ The proposal of the ‘active’ wall was extremely powerful — framed not as something that seals one part, but rather something that acts as a mediator between two conditions. We’ve somehow forgotten the relationship between the interior and exterior, which has had a huge impact on the climate as well as our perception of exteriors. Urban heat islands occur because we're not designing the envelope in relation to the city. The projects confront and challenge notions of comfort and the idea of living within a totally sealed microclimate. What other parameters defining the way we build, do the projects address?

STEFAAN JAMAER / PANTAAt the beginning of our process, we were intrigued by aspects of land use; our research began through trying to understand the relationship between land use and climate change in general. The idea of using plants to cool an interior led us to question how plants cool the planet in the first place; we tried to understand how that works more broadly. Then in the case of architecture and land use, we have a lot of regulation around surface permeability and drainage. Generally in Flanders, you must prove the amount of surface drainage versus the area of built or sealed surface that you're going to produce. This is a good start in making sure that we maintain the water table, which is healthy for the land and for the planet. But we believe it's possible to go further by introducing a biomass index per plot, encouraging the inclusion of vegetation even in dense urban construction. Our prototype explores this idea, including interior biomass as a viable metric. In that sense, it's a good case study.

KOOZ Stefaan, you have grounded Panta’s research within a modernist building; how did theseparameters of land useand the notion of biomass inform the way that you approached design?

STEFAAN JAMAER / PANTAWe asked ourselves what it would mean to return to pre-industrial levels of biomass, meaning a 100% biomass index per plot. In most urban contexts, this is nearly impossible without introducing vegetation into the interior. This prototype demonstrates how the principles proposed by Bas Smets and Stefano Mancuso could be applied architecturally. We aimed to recreate the biomass density that might have existed before industrialisation.

The biospheres are, in the case of this prototype, always interior spaces, because they take in air, cool it and use it to regulate the climate of a building as a whole. Our proposal includes greenhouse-like facades with operable windows, and roof-mounted devices that harness the airflow above the building, which stands taller than much of the surrounding cityscape. These devices make use of a Venturi effect, which is the effect of pushing a fluid through a tube. If that “tube” condenses, you produce an under-current which canthen be used to regulate the air flow through the building, bringing the air from the biospheres to the different levels of housing and the people who live there. A windmill, placed centrally, taps into the Maalbeek stream which runs directly under the building, to irrigate the biospheres.

KOOZ What drew you to identifying a particular type of building — the modernist housing block — as a reflection on modernism, orthe relationship between modernism and climate?

STEFAAN JAMAER / PANTAOur first objective was dealing with housing in general. In Belgium, there are two dominant types, which is probably typical for European cities in general. You have the maisons de maître, the typical 1900s bourgeois house, which make up large parts of the cities of Belgium — or the larger, more recent developments. In the 1970s there was a building boom of super-generic collective housing blocks; you find them all over Belgium, and actually you find them all over the world. So the choice was quite easy; one is universal on a European scale, and the other is universal on a global scale, which made our proposal a compelling and universal case study. Le Pacific, this particular building, is from the late modernist period, by which time many of the original ideals of modernism had been diluted. By introducing biospheres, we sought to reintroduce some of the lost values of early modernist collective housing, as imagined by figures like Le Corbusier.

KOOZ Thank you. Thomas, would you like to chime in? You're also dealing with that heritage, but rethinking it in a fundamentally different way.

THOMAS MERTENS / ELMĒS Well, Stefaan was indeed focusing on housing, and typologically speaking, the modernist housing block was indeed a good and interesting case study. By comparison, our interest stemmed from a certain theoretical position. Our understanding of this modernist project was partly related to certain new notions about environmental control; on how people can relate to their environment and to what extent they can control these environments. For example, in the catalogue of Building Biospheres, Veronique Patteuw elaborates on this notion put forward by Reyner Banham, who also tried to make an analysis of the introduction of mechanical equipment within architecture — what it means for architecture, and how we mediate our environment within our buildings.

We didn’t start from the Glaverbel building; rather, the project stemmed from looking at modernism, what that meant for environmental control, and then seeing how that translates into the new reality that we're faced with. Secondly, it also comes from a certain aspect of modernism; although it was a product of a particular context, it had a positive outlook on the future. We are now facing a future that is much more negatively or pessimistically approached. There's a similar effort to provide new interpretations of what the future could hold — but in our case, it’s about how we can save what is left or how we might compensate for mistakes already made. So from our side, it was a very conscious decision tolook at a modernist building.

I think the bio prototype also puts forth the different types of relationships we could have with our environment, with our sense of thermal comfort — which I think Steven, Maud and Lisa elaborated much further. For us, taking a Modernist building and placing it within this new reality was very conscious, therefore picking the Glaverbel building was partly a pragmatic choice. It was a pioneer of mechanical ventilation in Brussels, appearing very early in the 1960s; it is also a Modernist icon within Belgian architecture, so it was very well documented. There was a lot of archive material to delve into, so that we could better understand how these techniques were integrated, and what it meant in the sixties. You can see that the introduction of mechanical ventilation and this new way of dealing with the environment was, in a sense, very exciting for architects and for the client — but at the same time, they also had to confront their own ideas around the new aesthetics it created.

Within the archive material, there's a very funny documentation in which the building, if I'm not mistaken, was originally planned to have four levels. All around this perimeter, there were six little huts in which all the mechanical equipment for the ventilation was housed. They designed this entire thing, but the client and the architects were suddenly confronted with the reality of these mechanical ventilation boxes on top of the building. Such new aesthetic sensitivities wouldn’t pass so they submitted a new design, integrating another level to hide the ventilation boxes. This is also something we tried to understand; if this new technology has a certain impact on architecture, which new sensitivities are being created? If I may refer back to the catalogue, the text on Wild Aesthetics by Bart Decroos picks up on this. What does this new technology mean for our understanding of architectural aesthetics? I think it was a part of our effort to understand this and how it relates to this Modernist project.

VINH LINH / ELMĒS For us, it was very clear that we also wanted to work with an existing building to look at how this technology can be implemented. Because as we see it, the air-conditioning purpose of the biosphere is a technology; it’s not something from which you would begin an architecture. It's something that you need to implement or adapt, rather than the sole generator from which you could design. It became important for us to see how this technology could actually replace mechanical air-conditioning or work together with existing ventilation — also, what do you gain, what would you lose if you start to modify an existing building which has other values such as heritage, or landscape? How can you adapt this technology tothe building?

It was also important for us to actually use the tools of architecture to understand what it means — so drawings, collages, sections — to measure the type and size of trees, to measure the piping, to measure the light, to measure the soil, to understand the labour, maintenance and materiality which is at play and which would be needed to adapt our current environment. As such, we could reuse some parts of the existing Glaverbel building because the ventilation system was there, for example, but some parts — the biosphere and the garden — we had to take over. So for us, that overlay or modification was a very good case study, to understand what this technology would mean.

KOOZ These are speculations, but they're so deeply grounded in an understanding of architecture's potential. And the beauty is that between the four studios, you have explored very different tools and approaches; besides the curatorial direction of Bas Smets and Stefano Mancuso, it was a collective project. What did it mean as four young architecture offices to come together in presenting at the Biennale, in terms of moving beyond single authorship while using different approaches and means of articulation?

THOMAS MERTENS / ELMĒSI would also say it's a certain strength or a quality of Bas Smets and the Flemish Architecture Institute to have this lucidity, to invite four external offices beyond of the main curatorial team. Bas has mentioned this abundantly, but this notion of collective intelligence is indeed very important when introducing a new type of technology. To be able to give it away to see what outcomes there could be speaks, in a sense, to the value of the proposal; the willingness toput up a hypothesis, to be tested in other conditions without the control of its initiator, to allow it to fail — I think this is very valuable.

KOOZ It's quite exceptional. How did participating within the Belgian pavilion create a space of experimentation where you were able to maybe test some of the researches that you wanted to develop?

MAUD GERARD GOOSSENSI think it was possible because landscape architecture was the starting point, touching architecture, but today still not actively participating in creating spaces. This made it possible for us to research in a broader sense, beyond the more rigid lines of architecture within which we mostly operate; designing not only for humans, but also for the plants. In that sense, it was really interesting; for all of us, these projects didn’t come from nowhere; these were things that we already were interested in. This was a nice opportunity to do architecture research in a broader sense.

LISA MANDELARTZ SCHENKI think that the exhibition context is always nice for architects; because you can put forward an idealistic vision so that your idea can be more sharp and clear because other factors as the context of e.g. client and budget are less complex. On the other hand, this collaborativeness reveals something about the problems we're obviously facing. We can only solve the problems if we no longer act in competition anymore; that is, if we help each other and together find some solutions.

STEVEN SCHENK What’s nice is that everybody addressed a certain aspect. In the middle is this plant life, and in each of the fragments, you can start to imagine the potential of a particular aspect, even questioning the core project of Stefano and Bas Smets; by dealing with existing conditions, one starts to question what the building is in a way. In the end, the discussion moved towards what tools one works with as a young office — what do you need to address, within the constraints of regulation and budgets to store carbon... I really felt a renewed fascination or belief in architecture, that it can really do a lot of things without disjunction between function and technology.

VINH LINH / ELMĒS On that last point: for us, the subject of technical aspects and technology, within our project, become more and more important. In almost any building, the ventilation and cooling system eats up to a third of your budget, or it takes up so much space that you have to deal with it as an architect. The research on a possible new technology — as proposed in the pavilion — made us look at other techniques in parallel. We thought that maybe we could also now start to value other parts, besides the technical aspects — even to look at ways of diminishing it. We learned a lot about what position we want to take towards certain modes of techno-solutionism. I think one shouldn’t ignore it or embrace it fully; it is a hybrid condition, perhaps, that we need to interrogate, and I think that's what the pavilion tries to convey. What we learn from it is rather to balance things and to always try to be critical with this technology as something we might feel obliged to use.

KOOZ Thank you for sharing that. You mentioned the exhibition as creating space for utopian thinking, but it's also important to understand how this utopia might land back on the ground, right? Do you have any thoughts about the relationship between the research presented and that which you might continue to develop in your reciprocal practices?

STEVEN SCHENK I think it’s about the knowledge and the insights we have gained from our discussions. For example, on how air moves when it's warm or cold, or when it becomes CO2 rich. We are working, at the moment, on a care home project — a building for people with disabilities. We could use all of these arguments really usefully with clients, to convince them to interpret regulations; for instance, we could reduce ventilation amounts drastically, due to principles on which we could elaborate. So I just wanted to state that this is very concrete knowledge that you can use to convince people to believe in the potential of natural intelligence. That was quite interesting to see. If you have the time to strengthen your vocabulary and grammar, it's really important. That's why such collective collaboration should be more of a rule than an exception; the Biennale shouldn't be necessary to make it happen.

THOMAS MERTENS / ELMĒSThat’s the main value; beyond the reciprocities between our own practices, it's about the debates that it launches on a larger cultural platform. That’s what is of value; the sense that we — together with all the other team members, and even with the other nations present in the Biennale — could launch a nuanced debate on critical and visionary responses to the crisis that we're confronted with; we can have discussions on the nuance of thermal comfort, or what our relationship to technology should be. That is the main value of this proposal.

HENRI UIJTTERHAEGEN Maybe it echoes the others, but the collaboration and the collaborative effort was really valuable. And besides that, as architects, we should remember that we can also set up different relations, and not only for us as humans. We act on a broader scale; this project is really focused on the idea that we can elaborate our scope as architects to create space that is for the ‘more than humans’. This was a really nice aspect of the project — to reconsider all these interactions, to rethink those relationships.

STEFAAN JAMAER / PANTAI think that in general, between the four of us, perhaps none of us would propose a new building. We all work with the notion of elements that could either replace existing components in buildings or towards reconverting whole buildings. In that sense, I liked your question about the opportunities offered by such speculations in reimagining our built environment. You can see this principle everywhere in the current climate of architectural writing and thinking. In the exercise of this pavilion, you are led to reconsider the environment that you can see directly. It makes it easier to reimagine cities, because it works with the framework of the existing structure. The idea of looking at the city as an adaptable thing — just by means of taking away facades and replacing parts of buildings — is indeed something that changed my own thinking about architecture in general over the past months.

KOOZ Congratulations again for coming together on this project; the collective power of the different perspectives and approaches made for an extremely strong proposal. Thank you all for sharing your thoughts.

Bios

Maud Gerard Goossens and Henri Uijtterhaegen, as an architect duo, seek new insights within the broad field of architecture ​from different perspectives and a shared enthusiasm for experimentation, thanks to an interdisciplinary approach. In a humble and open-minded manner, they strive to add value to our living environment through architecture. Both are teaching in architecture at KULeuven.

Panta is an architecture and furniture design studio based in Brussels. Architecture is approached as an open framework between user and artefact. Each project emerges from a reading of context, program, and atmosphere, yet maintains a sense of openness and flexibility in use. Panta was founded by Stefaan Jamaer in 2022. Stefaan Jamaer grad­u­at­ed in ar­chi­tec­ture and civ­il-en­gi­neer­ing at Leuven University and Politecnico di Milano in 2013. He was a project leader at OFFICE Kersten Geers David Van Severen.

Elmēs is a Brussels-based ar­chi­tec­ture agency that en­gages in ef­fec­tive projects, cap­tur­ing the fric­tion­al re­la­tion­ship be­tween the realm of ar­chi­tec­ture and the many lay­ers of re­al­i­ty. The agency was found­ed by Vinh Linh, Thomas Mertens, and Jochen Schamelhout in 2020. Thomas Mertens was a project leader at OFFICE Kersten Geers David Van Severen and he also holds a bach­e­lor de­gree in eco­nom­ics from VUB. ​​Vinh Linh was a project leader at ar­chi­tecten de vylder vinck tail­lieu. From 2014 to 2021, he was teach­ing with Jo Taillieu at the EPF Lausanne and he is cur­rent­ly teach­ing at La Cambre Horta ULB. He is a found­ing mem­ber of Architecture Curating Practice.

Lisa Mandelartz Schenk is attached to the Chair of Housing at RWTH Aachen University. She studied Art History and Social Sciences in Basel and Monument and Landscape Care in Antwerp. Steven Schenk teaches at University of Applied Sciences in Bern and is working on a PhD. He studied Architecture at the University of Antwerp, the Accademia di Architettura in Mendrisio and ETH Zurich.

Federica Zambeletti is the founder and creative director of KoozArch. She is an architect, researcher and storyteller whose interests lie at the intersection of art, architecture and regenerative practices. Prior to dedicating her full attention to KoozArch in 2024, Federica collaborated with the architecture studio and non-profit agency for change UNA/UNLESS working on numerous cultural projects and the research of "Antarctic Resolution"