Matthew: Gabu, Bostjan, thank you so much for taking the time to talk to me. How did you approach this new unit brief, and how was it informed by your own work?

Gabu: I'm a practicing architect and theorist and my teaching brings these two topics together. I'm also an activist engaged in public issues, which sometimes relates directly to architecture and sometimes doesn't so much, but very often tackles urban questions and conflict in the city over public space. Last year, I led DIP17, covering radical democracy, architecture and urbanism. And this year, I'm super happy to be working with Bostjan, to bring together our two notions, which are the publicness of architecture, and the need for porous boundaries that define publicness.

Bostjan: I am also a practicing architect and an educator, and the architectural office I set up with my partner 24 years ago has been interested in the idea of planting or materialising publicness into spaces that haven’t originally been designed with publicness in mind. Porosity is the other key term we deal with in the office and in the unit, alongside publicness, and those ideas bring mine and Gabu’s work together. We want to apply that idea porosity not just to physical architecture and space but also connect it to the environment, social processes and so on.

Matthew: I wanted to ask about this idea of porosity. When I think about porous public space I think about the ability to move through something, but maybe that is too simplistic. Do you want to expand a little bit more what porosity means?

Gabu: If we think of it in spatial terms, porosity is actually exactly what architecture is about. We need to define a boundary, which actually opens up space. So it's not permeability, it's not just a doorway or an opening, porosity is really about spatial interaction of inside and outside, of accessibility. If we think of publicness it would be a misconception to have an idea of public space that was completely empty, open wide. Rather, creating publicness in space is defined by boundaries and porosity. Privatized public space is often not porous and excluding, so as architects we’re interested in challenging those spatial, legal and political arrangements.

Matt: So if I built a totally blank space in a city, that wouldn't actually be conducive to building a public space, things wouldn't thrive there?

Bostjan: You're very close but not completely there. To give an example, if you stand in Trafalgar Square and someone asked, “how would you increase the publicness of that space?” In order to generate publicness, one would need boundaries. So a vast blank open space could be improved by creating boundaries and spaces within the whole, with their own micro-ambiences, to stimulate different uses of that public space. You can then increase the attraction of the space to different user groups, increasing the different micro environmental conditions within that space. Porosity defined in physics is the ratio between solid and void in a mass, always spatial, always in three dimensions. And this is actually a link between the porosity and kind of dealing with architecture, because it's dealing with spatial characteristics, spatial sequences.

Gabu: Architecture at the end of the day is about creating voids. It can be an enormously large plaza, as you mentioned, but to grasp it as a plaza, it must have edges. And what is important is boundaries are not borders. Boundaries are not fences, not necessarily kind of strict lines, boundaries have depth. They actually may be thresholds, they may be inviting you into the space. This is not to say we need to strongly divide space, as in gated communities, as this is exactly the opposite of what we're talking about; a gated community is not public and not porous. Public space must be open to all, secure, without excluding.

Matt: There’s definitely a political question here, in terms of how we organise the public realm. Where do politics come into these conceptions of public space?

Gabu: Politics are at the heart of the unit’s work, and I am super happy that students are political again. There was a time that political thinking went out of academia, but it has returned. We have students who engage with politics aside from architecture, on the streets, in protest, and so on. We understand architecture is not neutral. But it's also not per se, good or bad. If we fully understand architecture to be a public thing, and especially dealing with public space, with burning issues that relate so much to architecture, then it is about literally taking a political position. Ant that´s something that you can discuss so much easier when you're a student than in real life, when you have the freedom to form your convictions and your beliefs about the world. Architecture may strive to be bold and claim to be for justice, to be just architecture, but at the same time, it's just architecture, it's only architecture and nothing more. And you have both of these senses entangled with each other.

Bostjan: What we'll be trying to achieve in the unit, is really to understand and to make students understand what is their power as architects. How can you be really an active contributor to the change in society, in the domain of the public space, as an architect, with the tools to hand, your skills, experience, and how you act as an architect, not as a sociologist, not as a biologist or anything else, but as an architect. We are asking the students to intervene in their chosen site in their respective cities all around the world. And at the end, they speculate what urban and social effects might be generated or catalysed by their intervention. Asking what is actually the impact of the architects’ role in society?

Gabu: The unit is also about self-initiating projects, teaching these upcoming architects to write their own brief for the project. The students tackle political and spatial issues as they exist in those contexts. They may be very different and also very local, and that's the beauty of the AA and our international units. We can talk across different contexts and the students can understand that their project is specific to its context, but can also be prototypical for larger, regional and global issues. These issues are sometimes so big that it seems impossible to tackle them. How can you stay humorous, maintain agency, and act on a pragmatic utopianism or utopian pragmatism? We architects must become more active and propositional in shaping the world, not just being what in German you would call dienstleister, a contractor or service provider. An architectural education can be very powerful because architectural projects propose something that is an alternative to an existing condition. It is powerful in the current moment when culture tells us there’s no alternative to neoliberalism, when the point of architectural projects are to show alternatives, to show how the world could be different. At the end of this year in our unit there will be 12 self-initiated propositions that offer an alternative to the ways things are now in the planned and built environment.