Emerging practices, new ideas

CB: I think architecture is a popular career here for two main reasons. First, in Paris, we have many architecture schools (around six) and 20 more across France, making it a relatively accessible course of study in terms of proximity all around France. Secondly, the architecture profession and the practice are changing rapidly toward a more sustainable approach . There are big, well-established firms that have a certain way of practising architecture. Indeed, adapting to new materials, economic shifts, and social contexts is challenging. These firms are often slow to embrace new approaches to building and design, while younger architects tend to approach the profession differently. We studied architecture and started by working in established firms, and learned the craft like one learns music, without questioning. We just played the sheet music like we had learned it. But after five years, repeating the same thing over and over, we had enough; we wanted to be closer to our convictions. We believe it’s necessary to question the practice, to approach architecture differently by challenging it.  Many young architects are striving to practise architecture in ways that align more closely with their beliefs. It is the same for us, and, in a way, that’s the reason why we decided to start our own agency, Belval & Parquet Architectes.

PP: Besides that, I also think that architecture and politics are deeply connected in Paris. Many social operators want to build differently, using alternative materials—less concrete, for example. This creates opportunities for us, as seen in our social housing projects. Paris is a dynamic environment in that sense. For instance, a few months ago, the City Council introduced new urban bio-climatic rules. This shift is an ongoing process—emerging practices are introducing new ways of building, prioritising transformation over demolition, while politics is beginning to translate these ideas into reality. In Paris, this connection between architecture and politics is particularly significant at this moment. This is a major movement that started a few years ago. We began our architectural studies at the tail end of this, learning from professors who were rationalist architects. We studied architects such as Auguste Perret and Jože Plečnik—figures who shaped our understanding of architecture. These influences instilled a strong sense of structure and rules, but our generation is now rethinking materials and how they shape architecture.

Designing with communities

PP: In Paris, we often engage in co-design with residents. We even won a project based on this topic, in collaboration with Dreier Frenzel Architecture, an architecture office based in Lausanne. The project, called Lepage, is located in the ZAC Saint-Vincent-de-Paul, in the 14 Arrondissement. The ZAC Saint-Vincent-de-Paul is an urban redevelopment project in Paris on the site of the former Saint-Vincent-de-Paul hospital. It is a mixed-use eco-district led by the City of Paris and developed by Paris & Métropole Aménagement (P&Ma). 

CB: We were selected to design this collective building, not with a completed design, but purely with a co-design process that involves the community of residents. After winning, we met with the residents and had to design the project together. It was really exciting. It’s an opportunity for true engagement in every aspect—architecture, materials, design, and urban planning. We bring architects, citizens, future residents, and politicians into the same room. 

PP: It’s a 33-unit housing project, with 23 units designated for future owner-residents and 10 for social housing, fostering a mixed community. Given the collaborative nature of the project, we proposed two approaches. The first was based on fixed architectural elements—certain aspects of the design, such as the building’s structure and window layout, were established from the outset. These decisions, made independently by us as architects, provided a framework that helped organise the project efficiently. The second approach focused on flexible elements, allowing residents to contribute to decisions on space distribution, shared areas, and flat locations. We engaged closely with them, asking questions such as: What spaces do you want to share? Where would you like to live in the building? Do you prefer the first floor or the seventh—and why? Who do you want as your neighbour? This participatory process helped shape a living environment tailored to the residents’ needs and preferences. Since we had to determine where each family would live, it became a complex puzzle—especially since nearly everyone wanted to live on the seventh floor!

CB: Ultimately, we incorporated design elements that accommodated different lifestyles, always striving to provide the highest quality for each space. For instance, while the ground floor is often considered less desirable, we designed duplex-style homes—like small city houses—offering an appealing option for those interested in a street-level experience. These homes combine direct street access with a more intimate and independent second-floor space. On the middle floors (2nd & 3rd), we made standard flats, more conventional living spaces. And finally, on the upper Floors (4th–7th), we introduced terraces and balconies to create a Bel Étage concept, inspired by classic Haussmannien buildings, where the first floor was traditionally for industrial use, and the upper levels were more desirable for living.

PP: Since the cost remains the same regardless of floor level, we designed a variety of living experiences to accommodate different needs. On the upper floors, a large shared terrace fosters a sense of community. Residents were encouraged to consider: “Do I want to live near shared spaces, or do I prefer more privacy?”

CB: We also included three adaptable spaces on the third and sixth floors—multifunctional rooms with no fixed purpose. We placed them in strategic locations to ensure no one side of the building had a significantly better spot. These rooms became collective spaces for children, workshops, after-school activities, and creative use. Throughout the project, we prioritised shared spaces in the most desirable locations to avoid favouritism, ensuring an equitable living experience for all.

CB: At the first meeting, we shared our initial selection, presenting the plans and elevations of the building and assigning locations to each family. Some families were in tears—it was a very intense moment because some really didn’t want to be on the ground floor. There were a lot of dramatic situations, but it was also a productive meeting. We asked three key questions: Why do you like or dislike our proposal? Do you like your neighbour, and which neighbour would you prefer? And where do you want to live in the building? After gathering responses, we considered everything and, in the next meeting, presented the final arrangement. In the end, it worked out, though three families decided to leave.

Scaling new materials

CB: When it comes to materials, we try to propose and use a variety of them, and today, that’s an opportunity for several reasons. The first is comfort for the inhabitants. Hemp, for example, greatly improves indoor living conditions in terms of air quality and thermal comfort.

PP: In 20 years, Paris will have the same climate as southern European cities. This change is happening fast, which is why we need to act now. Hemp is a great response to this challenge, especially for summer comfort. It’s also a local material—there’s plenty of hemp cultivation around Paris, just like straw.

CB: The difference between hemp and straw is that straw requires a significant amount of material to achieve good results. However, its size is already determined by agricultural production, making it easy to use. It’s essentially a prefabricated module, like in the Lepage building, where we used straw for the façade. The walls are about 60 cm thick, corresponding to the size of the straw bales, and are then covered with a protective natural layer.

Inside the building, we also need to consider materials that provide thermal inertia. Bio-sourced materials like hemp and wood don’t offer that, so we need concrete for certain structural elements. However, we’re also experimenting with earth construction techniques, or we use stone, as in our Montrouge project, where we designed 10 social housing units with solid stone on the street side, maxi-brick on the courtyard side, and timber floors. Maxi-brick is a type of large-format clay or concrete brick used in construction for its thermal and acoustic insulation properties. It’s not about being against concrete but about using it where it’s truly necessary. Concrete is essential for some structural elements, but in many cases, we can replace it with other materials.

PP: One of our main challenges as an office is to reduce the use of concrete in large-scale projects like social housing. In France, raw earth construction is mostly used for small-scale buildings, but we aim to integrate these techniques into larger urban developments. Every day, we ask ourselves: Is concrete truly necessary here? What alternative can we use? In Montrouge, for example, we designed a hybrid structure that thoughtfully combines different materials, striking a balance between durability and the urban context.

CB: Beyond material selection, we also consider how different construction methods shape the architecture. We’re not just engineers; we’re architects, so it’s about how these choices influence space. It’s not just about reducing concrete but thinking about what these materials create within the flats. The relationship between structure and architecture is fundamental, not just about efficiency but about shaping the experience of living in the space.

Fast, solid growth

PP: Our practice has grown quickly. We won competitions just two years after starting the office, and since then, we’ve worked across architecture, urban design, and research. Writing and exploring ideas have been part of our growth. The current context in Paris has also played a role, providing opportunities. The challenge now is to develop an office that can handle all of these aspects while staying true to our vision.

We collaborate with many architects, sharing ideas and discussing materials every day. The first part of our growth has been about learning from those around us. But beyond that, we also ask ourselves why we want to grow and how. We don’t want to become just a small team of two or three making compromises. If we want to bring about real change, we need to build something bigger.

CB: The real challenge is maintaining quality and ambition in every project. As the office grows, it’s easy to lose intensity, to take on projects that don’t receive the same level of engagement. That’s what I find most difficult—making sure that every project we work on gets the same dedication.

PP: We talk about every project, every day. Even if it’s just for five minutes, we make sure each one gets attention. But now we have about 15 to 20 projects running at the same time. Five minutes per project adds up—it makes for long days.