This conversation with architect and professor Sophie Delhay is part of a broader discussion on the project of housing that is ongoing at Burning Farm. Like the previous practices we interviewed—Lacol, SUMMACUMFEMMER, Plan Común—Delhay has produced some of the most experimental housing projects of the last decade.   

Founded in 2010, Sophie Delhay’s Paris-based practice stands out for its exclusive focus on housing design. With a particular interest in collective and social housing, Delhay completed several notable projects in France, mainly in Dijon, Lille, and Paris. She also formerly co-founded Boskop, an architectural cooperative in Lille, with whom she completed her first housing project, consisting of 55 social and experimental dwellings in Nantes—a widely acclaimed project based on the so-called ‘nappe’ or pattern typology, a recurring theme throughout her work, both in her practice and academic teaching.  

Our interview with Sophie Delhay offers insight into her approach to housing design, including the intricate relationship between private and collective spaces within housing and the constant tension between variation and repetition that characterizes her approach to designing large housing. Delhay explores the tension that arises when an architect designs housing between the desire for clear architectural forms and the need to allow architecture to fade into the background. In our interview, we discussed the current state of social housing, client expectations, and market pressures, in an effort to question the relationship between research and practice. 

 In 2019, her office was awarded the Équerre d’Argent following the completion of the ‘Unité(s)’ housing project in Dijon. This building—which is based on the repetition of identical rooms, thereby offering a variety of uses within domestic space—can be read in alignment with other European practices that repositioned the ‘room’ as the essential element in housing design. In 2022, she was also awarded the Schelling Prize in recognition of her work at the intersection of architectural theory, social engagement, and the realization of significant buildings.  

Interviewer: Romain Barth; Theodora Giovanazzi (BF)

Interviewee: Sophie Delhay (SD)

BF: Let us start from the very beginning of your career. You grew up and studied architecture in Lille in the 1990s. At that time, OMA and Rem Koolhaas were working on one of France’s largest master plans, Euralille. What role did this context play in your architectural education, and how did it shape your understanding of architecture?

SD: During my studies, I organized site visits to multiple Euralille projects and met with various professionals, schools, and journalists, while construction was ongoing. This was an important learning experience, as I had to present large-scale projects such as Congrexpo across different levels, from the urban scale down to detailed elements. In this sense, the project played a significant role in my formation. To clarify: my parents were architects. They ran a practice called FM Delhay in Paris. They collaborated with OMA for the Euralille masterplan and, more specifically, on the Congrexpo building in Lille. At that time, the Lille School of Architecture was not closely connected to this urban masterplan, partly because it was still perceived as a small, peripheral town, whereas the aim of Euralille was to position Lille as a European city. My connection to Euralille was therefore passive, mediated through my parents’ work. I chose not to work at OMA in order to avoid having any more privileges than my peers and to maintain a certain distance from these projects, even though I was inevitably connected to them. I am not sure whether this was the right decision, but ultimately it allowed me to forge my own path as an architect. A concern for equity has always been central to my career.

BF: Since you founded your own practice, Sophie Delhay Architecte, in 2010, in Paris, your work has been almost entirely dedicated to housing, including social and cooperative housing. Few offices have committed their practice to the project of housing, which makes this focus particularly striking. Where did this decision come from?

SD: It is partially a deliberate decision and partly the result of my personal trajectory. Before founding my own practice, I cofounded a collective office in Lille called Boskop, made up of three young architects and my father. We won first prize in a highly experimental competition focused on social housing. At this time, this was a new field for all of us, including my father, who had not previously worked on housing projects. We were selected for the competition based on our response to a single question: “What are experimental and innovative urban housing units?” The application required only a single A4 sheet, which gave us the opportunity to participate without prior references, which are usually required to enter such competitions. In the end, we won. During the competition phase, the client was still uncertain about the exact site. This meant that we had to take a strong position on the housing typology itself. The project eventually led to fifty social housing units in Nantes, completed in 2007. Unfortunately, the workload proved too intense for such a young team, leading each of us to go in different directions.

In France—and I imagine it is similar elsewhere—without prior references, it is almost impossible to enter competitions. After winning the competition, I could use this first housing project in Nantes as a reference. Although I tried to apply for competitions for schools and other programs, it never worked out. At a certain point, I began applying only to housing competitions. Later on, I made the conscious decision to dedicate myself exclusively to housing and to assert this focus as a position. I wanted to place housing at the center of my work, whereas for many architects it remains something done in parallel, often to secure a steady workload while pursuing other public commissions. Building on my first realized project, I chose to concentrate on housing and its social questions. I came to see it as a genuinely fascinating field, one that, ultimately, really matters. Moreover, working on housing requires significant effort with relatively limited budgets. At the same time, I became a professor in France, which allowed me to find a certain balance.

BF: Let us turn to your practice more broadly. The notion of the “protocol” appears to be central to your work, from your early project with Boskop in Nantes to more recent ones such as the Unité(s) in Dijon, completed in 2018. How would you define a “protocol,” and could you elaborate on this through some of your projects?

SD: The protocol is central to all my work. A protocol is a strong idea introduced at the very beginning of a project; it is a goal you set for yourself, one that is not defined by the brief. It is not a question but rather a position. The protocol is the means by which you pursue that goal through architecture.

What is interesting is that the boundary between methodology and architecture is not clearly defined. For example, in 2014, I was selected for a competition with another architect, Raphaëlle Hondelatte, for what would become the LoBou project. We realized that we could develop two separate buildings, each designing one. At the same time, we established a method for the shared space: if we, as architects, could share space, then the project itself could also incorporate this opportunity. This is a form of protocol: a way of developing a methodology that allows you to engage with the project by addressing what you consider its essential aspect. In that sense, protocol is an architectural means of working through a conceptual question. The protocol is a way of transforming the brief, which is often not very stimulating. As an architect, you rarely feel any real excitement when reading a competition brief, and it is usually full of contradictions. The challenge, then, is to bring these contradictions together in order to construct a strong architectural position.

BF: Often, the protocol seems to function as a framework that makes the project legible, and therefore acceptable, not only to architects but also to developers or housing providers. Does the protocol allow you to operate within the logic of today’s housing market while subtly reconfiguring it from within the project itself? For example, in your recent housing project, 35 Collective Dwellings in the Messageries neighborhood in Paris (2025), by doubling the stair core, each apartment can benefit from a view of the park, something that would not have been possible within the conventional “urban villa” typology.

SD: For developers, the urban villa is often considered the most efficient typology, as it readily accommodates speculative logic. This was, in fact, the main reason it was adopted in the master plan. However, by following this model, we realized that only half of the inhabitants would benefit from views of the park—the most desirable orientation—while the other half would not. In response, we proposed that all apartments should have equal access to the park view, so that every resident would be equal. We were fortunate to have a receptive jury, and we won the competition. When the results were announced, I asked the client, “Did you understand that we are proposing two stair cores instead of one?” He replied, “Yes, but in your project, all the apartments face the park and are south-facing. For you, as architects, this solution works, but for us too, because we can sell the units at a higher price. It’s a good deal.” In that sense, different interests can sometimes align.

This apartment layout avoids the need for four complex facades, where bedrooms and living rooms share the same elevation but require different window sizes. Instead, three facades are treated with the same linear windows, while the façade facing the park is given more generous openings.

BF: You often disrupt the repetition that structures your plans through the façades, showing that variation can emerge even within a repetitive framework. In other words, your projects are often based on a compositional logic of repetition, yet this very repetition allows for a diversity of uses. We are thinking of the recent Chère Catherine project in Montreuil, or the 100 Kitchens project in Munich.

SD: I do not have a single answer, but in every project, I try to address this question. It is true that standardization is often associated with repetition, but I prefer to think of repetition as a way of encouraging a collective condition. One could say: “I live in a collective building, everything is repetitive, and therefore my window is identical to the others.” But in that case, repetition becomes restrictive, because it imposes a single solution for everyone. If you cannot adapt to it, you are effectively excluded. So while working with repetition can be productive, it is essential to incorporate diversity. For example, in the 2021–22 project 95 Connected Kitchens, in Dijon, there are two distinct façades. This results in two types of windows, corresponding to two different spatial conditions.

In Munich, however, I pursued a different approach. I designed two contrasting facades: the courtyard façade is entirely repetitive and expresses the collective dimension of the project (it is where the kitchens are located, one hundred in total). On the opposite side, the façade forms a collective pattern composed of four different window types, each producing a distinct atmosphere for the bedrooms, which all face this side. Thus, although the project is based on repetition, each apartment contains four rooms that are identical in size but different in their relationship to the exterior.

Jacques Hondelatte—who was my diploma professor—once wrote that he would like collective housing to offer a collection of atmospheres rather than a collection of programs: humid spaces, luminous spaces, and so on.⁠ The Munich project can be understood as an attempt to translate this idea into built form, within the constraints of a modest social housing budget.

In that sense, the project explores how repetition can accommodate diversity. However, this approach only works at a certain scale when there is a large number of units. With only a few apartments, the effect would not be convincing. Ultimately, these two facades represent, for me, two ways of engaging the collective scale: repetition with diversity, and repetition based on uniformity.

BF: Across your projects, there is a clear resistance to functional hierarchy and conventional spatial distribution, particularly in your use of rooms of equal size and your avoidance of predetermined uses. The focus on equal rooms as a design strategy also appeared in the work of other European practices, as seen in Dogma’s Live Forever: The Return of the Factory (2013) in Tallinn, Peris+Toral Arquitectes’s 85 Social Housing Units in Cornellà (2019), or MAIO’s 40 Hierarchyless-Spaces Social Housing Units in Barcelona (2021), among others. In this sense, your work could be seen as part of a broader position, or interest, within contemporary architecture.

SD: Yes, although I am speaking from my own position, it was remarkable to discover that at the same moment in different places, such as Zurich, Barcelona, Paris, and Brussels, architects were working on projects based on equal rooms. That said, I do not always work with equal rooms. The Unité(s) project in Dijon became widely known, but I often emphasize at the end of lectures that I am not exclusively designing this type of project.

Housing is a very particular field within architecture because it necessarily involves the inhabitant. For me, this creates a tension between the architect’s decisions and real life. This tension is crucial in every project, and depending on the conditions, it can produce very different spatial outcomes. For example, in the Chère Catherine project, which was based on a participatory process, it was the first time I could directly engage with the inhabitants. At the same time, I wanted to maintain a strong architectural position, working with them, but also, in a sense, against them. I aimed to be even more generous than before, intensifying the tension between my proposal and their way of living. I sometimes say that I play with fire: I invited the inhabitants to take part in the design of the façade. They designed the courtyard façade, a more intimate, collective face, while I designed the street façade, which engages the urban context.

What interests me is how this process questions the discipline itself: it challenges your values, working conditions, methodology, and relationship with the client. I find it difficult to define this tension precisely, although it remains a productive and compelling issue for me.

For instance, in projects with equal rooms, the architect makes a very strong, almost authoritarian decision at the outset. Yet ultimately, the aim is to provide greater freedom for the inhabitants. This may be a more philosophical question that I constantly return to: how to reconcile one’s own life with one’s role as an architect.

BF: We are reminded here of your working method of délimiter sans limiter, to delimit without limiting, as Anna Rosellini describes it in her essay on your work: designing opportunities for inhabitants without prescribing how this space should be used, a difficult tension in architecture.⁠

SD: Yes, and I have no issue with this tension. I am a designer, and I strongly defend that position. But in my own life, I am also an inhabitant, and I know that inhabitants are themselves experts in use. For example, when designing a theater, users are less directly involved, whereas in housing, everyone has an opinion, and all these opinions are equally valid.

BF: In your work, repetition can generate a variety of uses. In that sense, architecture becomes the background of life.

SD: Yes. After the 55 Dwellings in Nantes project was completed, everything was new, bright, almost shiny, and in photographs, architecture always appeared in the foreground. But I often said that I wished the building were older, because in reality, architecture should not occupy the foreground. It should recede, becoming secondary. In the end, architecture is something you should be able to forget.

BF: You regularly return to your projects to photograph them. This is a strong testament to your commitment to the inhabitants that goes beyond your role as a designer. These post-occupancy visits also seem to be crucial to your practice. For example, you mentioned that after revisiting the project in Nantes, you realized how important the kitchen was for fostering collective life in the shared courtyard between four units. In your more recent projects, the kitchen appears to have taken on an even more central role.

SD: Yes. After the project in Nantes, I wanted to explore more collective forms of housing. Today, it is quite common to include shared spaces in social housing, but around 2010, this was not the case. For the Machu Picchu project in Lille, completed in 2014, the clients initially refused any collective spaces. I therefore had to find a way to encourage collective life without relying on dedicated shared areas. It had to emerge from within the dwellings themselves. My question became: How can housing units be connected through their kitchens? In this way, no additional surface area was required.

BF: The kitchen seems to have become a social and collective device in your work. In the 95 Cuisines Connectées project in Dijon, all the kitchens face an external gallery, or circulation space, and can extend outward with a small table, almost like a continuous bar. Along this shared gallery, you also introduced a long beam table for collective meals. Similarly, in the housing project in Munich, all the kitchens face an outdoor gallery.

SD: For me, the beam table addresses a recurring question: how to provide collective spaces even when they are not part of the brief. I could present it to the client as a kind of extra, but if it remains at that level, it will inevitably be eliminated during the process. The only way to ensure its presence is to integrate it into the architecture itself, as a firm and necessary decision. That is why the collective table is, above all, a structural element.

BF: This brings us to your broader research on eating, sharing meals, and cooking. In many of your projects, kitchens are directly connected to shared spaces. Over time, the kitchen seems to have gained autonomy and become a central element. Could you introduce your research on the kitchen, including your academic work, and explain how you came to see it as essential and placed at the core of the project?

SD: At EPFL, our Domestic City Laboratory focuses on domestic space, and I wanted to address collective domestic space. I had the intuition that the kitchen could serve as a useful tool for the students, because it is such a lively and familiar space. At the beginning, I understood it primarily as a social device within the project. The students started by analyzing kitchens that have the capacity to bring people together. Over time, we realized that the kitchen is closely related to climatic conditions but also a highly political space where power relations are constantly at play. Finally, we acknowledged it as a hedonistic space as well, one that can establish direct relationships with the outdoors and evoke a sense of leisure, even of holiday. As a result, we decided to focus on these four dimensions of the kitchen.

For architects, the kitchen has traditionally been treated as a backspace, something secondary that is rarely placed at the fore. Today, it is becoming more present in architectural discourse, but in social housing in particular, it is still often overlooked. I was therefore interested in pushing this further by presenting the kitchen as a central protagonist. Moreover, the kitchen intersects many contemporary concerns: it relates to climate, to new ways of living, to social dynamics, and ultimately, to the question of how to design spaces that are genuinely pleasurable to inhabit. We studied this topic with students for over four years. In total, we analyzed and redrew 100 kitchens, organized according to these four categories. This material will be published in our upcoming book Kitchen Powers: Social, Climatic, Hedonist, and Political Perspectives.

BF: Can you explain how your research on the kitchen has informed your projects, particularly those in Munich and Dijon?

SD: In the Munich project, one of the more experimental aspects was the need to create larger rooms. I had worked on many projects with very small rooms, so here I decided to eliminate one element of the program altogether: the living room. As a result, each room could function as a living room: the kitchen becomes a living space, the bedroom as well, and so on. It was a way of making a strong decision in response to the many contradictions within the competition brief.

BF: One aspect that we find particularly compelling in your projects is their strong resistance to the neoliberal context in which we are forced to operate. Your projects seem to counter the logic of the market, not only through the introduction of shared spaces, but also by proposing shared forms of living that complicate the notion of private property.

SD: Yes, my position can be understood as a form of resistance, but it also has consequences for one’s own life. My practice and my team remain quite fragile. This means that you have to accept the implications of such choices. If you want to build a larger, more stable office, it becomes difficult to focus on social housing because it demands a lot of work from a team, yet it is poorly paid. In this way, this kind of work receives little recognition.. So, this position inevitably dictates a way of living. I would also say that practice and teaching are deeply interconnected. Teaching provides the conditions that make my practice possible, and practice, in turn, nourishes my teaching. The two are inseparable. If you want to engage in this kind of civic resistance, you must operate on both levels: in built work, but also through the education of future architects. To change things, you have to act in the real world, but you also have to support and encourage younger generations.

AUTHOR

Sophie Delhay is an architect and the founder of Sophie Delhay Architecte since 2010. She is also a professor at the École Polytechnique Fédérale de Lausanne, where she heads the Domestic City laboratory. 

Romain Barth and Theodora Giovanazzi are editors at Burning Farm and collaborators of the TPoD lab at the École Polytechnique Fédérale de Lausanne.