FEDERICA ZAMBELETTI / KOOZ Rotor defines itself as a cooperative design practice that investigates the organisation of the material environment. Could you expand on how you define and approach the material environment?

MICHAËL GHYOOTI would say curiosity is probably the main driver for everyone at Rotor. You may know that behind Rotor, we actually have two different structures. On one hand, there's a nonprofit organisation dealing with a wide range of missions, and on the other, we have Rotor DC, a cooperative company mostly focusing on salvaging building elements and furniture, and then putting them back on the market.

The statement you mentioned is indeed a bit vague, but it's also as concise as we could manage. There is a strong willingness among us to explore the built environment — how it is constructed and what materials constitute it. We pursue this through various types of projects. For instance, we conduct a significant amount of research, which usually involves field observation and site visits. That forms a big part of our documentary process. We also carry out research projects that result in reports, documents, or publications, which we share quite openly. Additionally, we communicate our findings through workshops and education — these are essential aspects of our work. Increasingly, we collaborate with contracting authorities and clients working on projects who want to integrate reuse strategies. We help make these strategies more tangible by inventorying reusable elements and offering advice on writing tenders, specifications and site follow-up. I should also talk about another important strand — interior design. We're not licensed architects (despite many team members having an architecture background), we don't define ourselves as practicing architects. Nevertheless, we do quite a lot of design work, mostly related to interiors or temporary structures. We often collaborate with architects in the context of the consultancies we provide.

Finally, we developed Rotor DC as a new economic actor in Belgium's reuse trade, with a focus on salvaging materials and reintroducing them to the market.

KOOZ The pivot towards the material environment — moving away from architecture and built structures — is intriguing. What informed your decision to emphasise the material environment rather than traditional notion of architectural structures and buildings?

MGIt's probably a complex notion, but to put it simply, it's really about the idea that everything around us is designed in some way — whether by architects, other professions, or even individuals who don't claim any particular expertise. This perspective is also inspired by the difficulty of distinguishing between what comes from culture and what comes from nature today. The environment is a mix of both, which relates to this Latourian idea that has influenced us. In fact, it was quite an inspiration in the early days of Rotor.

The notion of the built environment is particularly interesting because it encompasses both the natural world, as implied by the word "environment," and the concept of "built," which suggests significant interventions to shape and inhabit it.

KOOZ It's an interesting dichotomy between the man-made and the natural, emphasising your focus on individual materials rather than their compound forms. You mentioned the different scales that you approach — from salvaging building elements and working on interior projects to advising organisations. Is each project a unique process?

OLIVIA NOËLSome questions can be answered more easily when working on a small scale, while others require a wider perspective. For instance, when experimenting with reusing specific materials, the questions may be similar, but it's simpler to address them on a smaller scale. It's more manageable to deal with just a few square meters of terraces than sourcing or reclaiming a very large batch of materials, which introduces additional economic challenges.

For us, it's interesting to work across different scales. We take on very small-scale projects or missions, sometimes starting with just a couple of workshops to initiate discussions. At the same time, our biggest project involves over 100,000 square meters. There's no fixed formula for us. It's more of a "crafty" approach, understanding what the best solution is for the specific project, whether it's small or large. The way we work often begins with asking a lot of questions. Frequently, we don't provide the answers ourselves because we collaborate with very competent people involved in the projects. This includes not just the Rotor team but also the design team, construction team, legal advisors, and others who are specialists in their fields. By asking questions, we enable them to find the answers, as they are often more knowledgeable on specific topics than we are. In this way, it's not particularly difficult to move from one scale to another.

KOOZ Have you been able to identify any recurring questions?

ONUnderstanding what's already there is one of the first questions we address, and most of the time, it's an essential step. We rarely work on demolition projects or start from a blank slate. Instead, we're more interested in projects where there is an existing context — buildings, materials, and so forth. Clearly identifying the qualities, materialities and quantities of what's present is vital, whether for small or larger projects.

For example, drafting an inventory for a house is relatively straightforward. It takes just a few hours to go through the spaces, physically interact with the materials, and gain a comprehensive understanding. But scaling up can be vastly different — such as when the task involves broadening a road and demolishing 150 buildings. Conducting a full inventory of 150 buildings before starting is simply impractical. The same questions may arise, but the approach must be entirely different. When starting a project, we often define an initial mission — especially in the context of design assistance missions — and see how it evolves as we proceed. This approach remains consistent for design projects as well. We establish a starting point and refine our approach along the way based on the specifics of the project.

MGThere is a tension between, on one hand, an appetite for standardisation — one-size-fits-all solutions that the construction sector strongly demands — and on the other hand, the heterogeneous nature of reuse. Reused materials often come in smaller volumes, each aged differently, with slight variations in dimensions and characteristics. This leads to a high degree of specificity in reuse, and bridging that gap is not always straightforward.

A big part of our work involves addressing these challenges. We aim to adjust the expectations of the construction industry — whether clients or architects — by suggesting that there may be more flexibility than initially assumed. We work to open the range of possibilities. However, we also strive to professionalise the salvage and reuse trade. This is a major role for Rotor DC: collecting materials, sorting them, describing them, and providing enough documentation for their reuse in projects. By working on both these aspects — adjusting expectations and professionalising the reuse process — we aim to create a match between the industry's needs and the realities of reuse. It all remains a significant challenge.

KOOZ The commitment to working with what already exists — the "ready-made," as reflected in the OBEL Award theme — is truly admirable. Clients and developers often argue that it is significantly cheaper to demolish and build anew, despite its long-term benefits of adaptive reuse. How do you navigate this tension?

MGThat's a very good question. I think it's important to mention that in Brussels, there has been a paradigm shift in recent years, supported by several administrations, particularly the Brussels Bouwmeester/Maître Architecte. The last Bouwmeester, Kristiaan Borret, strongly advocated for the idea that demolition by default is no longer an option in Brussels — it should only be a last resort and must be duly justified. This stance has created a strong incentive from public authorities to move in this direction.

Of course, progress is somewhat slow because it requires rethinking the regulatory framework and implementing changes. However, there are solid administrative efforts behind this initiative to push it forward. This shift has also brought about a cultural transformation, even among large real estate developers. While there are still cases of premature demolitions that can be debated, renovation is increasingly becoming the norm. As a result, there isn't as much work needed in this area as there used to be — in Brussels, at least.

ONWhen a total demolition happens, we politely decline by making a statement over the phone. We explain that, as a general rule, we don't get involved in demolition projects, although we may make exceptions if there's still an opportunity for reuse. Sometimes, even just making that statement prompts people to reconsider, thinking, "Oh, perhaps I shouldn't be doing that, then." But this mostly applies on a smaller scale.

MG I think the most interesting projects we've accompanied are those where the client was open to adapting the program to the existing building, rather than the other way around. When you try to force a program onto an existing building, it often leads to new requirements that effectively discard the existing structure. However, being more flexible and agile in thinking about how a program can integrate into an existing building creates better opportunities for preservation.

Take the Zinneke project, for instance. In this case, the building owner or user was fully invested in this approach, aiming to understand the building's capabilities and determining what could be done with minimal necessary interventions to create a comfortable environment. This kind of flexibility is invaluable in preserving and retaining existing buildings on a large scale. For the Zinneke project, the calculations showed that approximately 89% of the existing building could be retained. Only small elements had to be removed or adapted for new uses. This was possible because the client designed their needs around the existing structure, rather than imposing something entirely new.

KOOZ Starting with the buildings that are readily available for functional transformation, to what extent have you been able to engage with clients who think in this way? Or has your experience been more about adapting a programme to the existing flexibility of a building — thereby working around the constraints of predefined uses and structures?

MGWe encounter a bit of both situations; it depends on the agenda. Sometimes, we work with commissioners who are still at a stage in the process where they can rethink or develop their programme. In those cases, it's very interesting to accompany them in considering what the building can offer and what it is capable of. Other times, we deal with briefs that are already quite locked and finalised. In such cases, the program may not be optimal for the building, which leads to more extensive work and transformations.

ONIn those latter cases, we also focus on the cultural perception of what already exists. Even when refurbishing a building for a specific use — especially when significant interventions are unavoidable — we aim to adapt the spaces with minimal effort. This involves working within what's already there by making small changes to perception, usage, or circulation rather than overhauling the entire process. Adjustments are necessary, but they don't have to mean completely rethinking the building. I mean, it's something that happens, right? Either the building is brought to a completely renovated state, or expectations for thermal comfort or other aspects are adjusted. Alternatively, adjustments can be made around the program itself and how it's implemented. This process is very much tied to the cultural perception of the building.

KOOZ In the practice of Mio Tsuneyama — who views architecture and the built environment through the lens of material cycles — it's not always about reuse, especially when the structure is too damaged. Rather it's about building anew while maintaining an awareness of the full material cycle of the elements used. How do you approach projects where reuse might not be the best solution?

ONI agree that one must look at the entire cycle of construction and building usage when comparing impact. I can't think of an example where building completely anew, even using only bio-based materials, would achieve a better result than conserving at least the structure of what's already there. I believe the answer lies in doing both: renovating with bio-based materials while carefully considering what you use. The reversibility of materials and how they are integrated is crucial because, in some cases, even bio-based materials cannot be reused, which introduces other challenges. It's a complex and complementary question. However, since we don't work on larger-scale architecture, it's a bit harder for us to have a strong position on the matter.

MGOne interesting point is the link between bio-based materials and reclaimed building materials. Neither, as of today, is entirely capable of satisfying the construction industry's demand in terms of volume. Over time, we've grown accustomed to building very large structures with materials that are predictable, available on demand, duly warranted, and standardised. With bio-based or reclaimed materials, the context is entirely different.

If you were to imagine constructing a large-scale building entirely with bio-based and reclaimed elements, the current market likely couldn't provide sufficient quantities. Moreover, if the markets for these materials grew significantly, they might lose some of their advantages. They could become industrialised "mega machines," potentially eroding their unique benefits. As a result, working with these materials often obliges you to engage with existing buildings and minimise the quantities of new materials used. This approach allows for an increased integration of bio-based and reclaimed elements.

KOOZ That's an interesting question, especially in relation to the concept of bio-regions, Returning to the idea of weight and materials, I'd like to understand the relationship between Rotor and Rotor DC two entities. Almost a decade after it was established, what effect has a practice like Rotor DC had on the industry and vice versa?

ONRotor DC was a spin-off from Rotor. It started with the idea of reclaiming materials and initially selling them directly from the site, then later from a warehouse. Over time, it became more structured, and today, it has outgrown Rotor, the nonprofit, by a significant margin. In terms of personnel, Rotor DC is now twice the size of the core team at Rotor.

We maintain a very close relationship with Rotor DC — they're on the same site, we share resources, and we collaborate daily. They've also become much more visible on social media, and people often confuse the two entities. We frequently receive questions or tags meant for one but directed to the other. We don't mind this confusion, as it helps people understand the broader scope of what we do and the different facets of reuse.

Rotor DC has inspired quite a few initiatives in Belgium and beyond. We see this reflected in the numerous requests we receive. Interestingly, we've found ourselves in a unique position as experts, assisting public authorities in supporting new initiatives, including those of potential competitors. We're okay with this — it aligns with our mission to test, research, and remain at the forefront of what's possible in reuse and circular economy practices.

The market is slowly catching up. It's fascinating to see how much reuse and circular economy principles are gaining traction. Of course, the market is now going through the same learning curve we experienced six to eight years ago, making similar mistakes and learning from them. Brussels politics have played a significant role in this shift, with strong support from the administration in terms of financing and promotion, both locally and internationally. As a result, we're often seen as an example by many on a global scale.

There are now more initiatives, each with its own business model — some as consultants, others as different types of organisations. However, we can't claim sole credit for this movement. It's the result of many factors coming together.

MGInitially, the concept was that Rotor DC would go on-site, dismantle materials, and then bring them back to the warehouse for preparation and reuse. We still do this — Rotor DC has a dedicated team with the skills, tools, and expertise to properly dismantle materials. For certain materials, they remain the best option.

However, what changed is that we began viewing contractors and even private clients, who are in contact with potentially reusable materials at their sites, as potential salvagers themselves. What we realised was this: as a contractor, if you know how to install a door, you likely also know how to dismantle it. Similarly, if you know how to install sanitary ware, you probably know how to remove it correctly.

The challenge for these actors was not in dismantling but in the logistics — they aren't salvage dealers. They don't have the clients, the market, or the warehouse space to store salvaged materials. This is where Rotor DC steps in. By offering the necessary infrastructure and pathways, we've enabled contractors in the Brussels area to act as salvagers. This has been transformative — a relatively small change that has led to a significant shift in the industry.

ONThis wasn't only the case with Rotor DC — it also applied to the Opalis network. Many of these dealers had already existed long before Rotor came into being. They've always been there, but they weren't visible, known, or well-documented. Through the Opalis network, we managed to make these dealers visible and activatable by the market as a whole. I think this was one of the key triggers for reuse. While the market was perceived as nonexistent, it was there. It's always been there, but hidden from view.

MGChronologically speaking, Opalis came before Rotor DC, and I believe it was a significant trigger in itself. We visited most of the salvage companies around Brussels and in other countries, documenting them in an online web directory. Through this process, we realised, as Olivia mentioned, that there was already a market for reuse — specialist companies capable of salvaging and preparing materials.

However, we also identified missing connections. For example, materials frequently discarded on Brussels demolition sites, particularly from more recent office buildings, were not well represented in the existing market. This realization was the main catalyst for us to say, "There's something to be done about these materials," and it shaped our role, ultimately leading to the creation of Rotor DC.

Another key factor was our observation that, when we started Opalis, salvage dealers were primarily located outside of city centers. Historically, this wasn't the case; archives show that 50 to 100 years ago, salvage dealers were central to cities. They were likely pushed out due to rising land prices, forcing them to seek cheaper land in more remote areas. We wanted to reverse this trend and bring salvage back into the city. That became an innovative aspect of Rotor DC's approach, as we saw cities as the nexus where demolition occurs and where demand for reclaimed materials is strongest. Although urban locations come with higher rents and require a high turnover to sustain operations, being embedded in the city is essential to us. It aligns with our vision of reintegrating salvage as a vital part of the urban economy, even if it's counterintuitive or challenging.

KOOZ It's truly inspiring how you operate with the ready-made across platforms; the beauty lies in creating these spaces of exchange — whether physical, online, or in practice. I'd like to understand ROTOR's role in shaping policy. How have your field observations influenced the positions you take, and what is your relationship to informing or contributing to policy development?

MG There's a specific contextual situation in Belgium that influences our work. The country comprises three regions, and the City of Brussels is an autonomous region with considerable authority over certain matters. For example, topics like environment and waste management are addressed at the regional level. However, Brussels is a very small region — essentially, a small city — which creates a certain proximity to public authorities.

We have a government in Brussels, complete with ministers and state secretaries, and we know where to find them. While we don't interact with them on a daily basis, there is a relatively close connection, including with the regional administrations. Over the years, we've built strong relationships with certain administrations, particularly those focused on environmental matters. This has been invaluable in conveying ideas and suggestions.

As you mentioned, our role in the lobbying ecosystem is to bring the voice of fieldwork into the political debate. We are deeply attached to this aspect of our work — it's incredibly important to us. Whether it's visiting companies, conducting on-site reclamation audits, or engaging with projects directly, we strive to be as close to the field as possible. This helps ensure that our insights and experiences can be effectively conveyed in the policy-making process.

ONI think one of our core principles is that we aim to experiment with everything we do, without being primarily driven by creating a business out of it. Once we've identified a solution to a particular challenge, we're genuinely happy if other people or companies take that forward as a new business. That approach gives us a certain credibility, as we operate as a nonprofit with a focus on broad social impact.

I believe this ethos encourages people to listen to us. They understand that we're not lobbying for personal gain, but advocating for the greater good. That's also why we're involved in so many public initiatives as experts — our goal is to give back and help people form their own ideas about various challenges. In a way, this is our way of promoting what we stand for and the changes we want to see.

MG One of the things we're quite good at is approaching the question of reuse in a very holistic way. For us, it's not just about overcoming technical obstacles — though those are, of course, part of the process. Reuse isn't merely a technical issue; it's also deeply cultural. It's about techniques, yes, but equally about aesthetics. It's about the present, but it's also rooted in history. We strive to juggle all these dimensions and bring them together in our work.

KOOZ Many offices are set up as for-profit organizations. You chose to establish yourself as a nonprofit. Was this decision part of your vision from the very beginning — a conscious effort to prioritise social good as the foundation of your practice? Or did this realisation develop over time?

MGThere are many factors that contributed to the decision to establish Rotor as a nonprofit. When we started, it was a small group — just three people — and initially, it felt more like a side project than a professional endeavor. You don't need any capital to create a nonprofit; all it takes is a few people signing the necessary paperwork, and you're set. This simplicity was an important factor at the time.

That said, I believe the mindset was already oriented toward a nonprofit approach. The versatility of the nonprofit structure was appealing because it allowed us to take on a wide range of projects without being confined to one type of mission. This flexibility has been crucial since the beginning, as we wanted to explore diverse possibilities without limitations.

Interestingly, when I revisit the official statutes that define our juridical structure, which we update regularly, I find that they have remained almost unchanged over the past 20 years. Everything was already there at the start — or open enough to be maintained for a long time.

KOOZ You mentioned that both the industry is picking up and that paradigm shifts towards a more regenerative form of practice are slowly advancing — this certainly seems to be the case in Brussels. Where do you see the greatest obstacles and opportunities in mainstreaming the idea and approach of working with what is already there?

ONI think the answer is that there is no answer, no single solution. Tackling this issue requires approaching it from multiple perspectives. It involves culture, economics, laws, logistics, the types of materials available, and certification. It's also about fundamentally rethinking the way we build. So, the short answer is that there isn't just one area to address — there are many interconnected aspects that everyone needs to work on to make progress.

This challenge extends beyond reuse and encompasses the broader circular economy as a whole. Escaping the constraints of the linear economy is incredibly difficult. That's one of the conclusions we reached during the recent “Entangled Matter” exhibition, which Rotor curated. It underscored just how deeply embedded we are within the linear economy, and how challenging it is to move away from it.

KOOZ How does this translate to the expertise within Rotor? What kind of backgrounds and areas of expertise does your team encompass, and how diverse are they?

ONOur expertise is quite varied, and it often depends on the specific research projects we're working on. For example, we've had team members specializing in public tendering or with backgrounds in law. I think being multidisciplinary is essential. Everyone in the team wears different hats and pursues different interests. Given the experimental nature of our work, we're constantly learning as we go. Many of the questions we ask ourselves don't have immediate answers, but we discover them through projects, one step at a time. What ties us together is our shared curiosity and eagerness to learn. We often gain new insights from private developers, for example, who share how they finance their projects, which opens up a whole new perspective and reveals challenges we need to address in our work. Ultimately, this ongoing learning process and adaptability make our specific backgrounds less relevant. It's more about our ability to explore, understand, and grow through each project.

Bios

Michaël Ghyoot is an architect and a researcher in the fields of ecology, reuse and architecture. He joined Rotor in 2008, developing many projects on the reuse of building materials. Since 2018, Michaël has been a full-time project manager at Rotor, where he is involved in research, lectures, organisation of exhibitions and assistance with the re-use of materials for building owners in Belgium.

Olivia Noël is an architectural historian with extensive experience in private and public project management, gaining experience working in the field of architecture and architectural culture, both in the UK and the USA. She joined Rotor in 2020 and coordinates the circular assistance missions, and is a member of the Rotor Deconstruction Advisory Board.

Federica Zambeletti is the founder and managing director of KoozArch. She is an architect, researcher and digital curator whose interests lie at the intersection between art, architecture and regenerative practices. In 2015 Federica founded KoozArch with the ambition of creating a space where to research, explore and discuss architecture beyond the limits of its built form. Prior to dedicating her full attention to KoozArch, 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". Federica is an Architectural Association School of Architecture in London alumni.