Thinking ahead about the end of life thanks to material passports

With the renovation of the Infocentrum into Vonk, Kamp C not only wants to create a future-oriented building, but also to initiate a learning process. Circularity, reuse, bio-based materials and knowledge sharing are central to this. Not only in the end result, but also along the way. That is why two PhD students are actively involved in the renovation process. Their research runs parallel to the project and fuels the debate on bio-circular construction in Flanders.

In this first interview, we speak to Amélie Halbach, a PhD researcher at the Faculty of Architecture at the University of Liège. Her research focuses on material passports and design for disassembly, and the question of how we can anticipate tomorrow's reuse today.

Anticipating reuse

Amélie graduated from the University of Liège in 2019 and then worked in architectural practice for three years. There, she quickly encountered a frustration: circularity rarely appeared to be a priority. "During my master's thesis, I was very interested in this, but in practice I noticed that it is often not a given. There is little time or budget for it." That experience led her to delve deeper into the subject. Since September 2022, she has been pursuing a PhD at the University of Liège.

Her research focuses on reuse at a specific moment in time. "I focus on how we can facilitate reuse at the end of a building's life," she explains. "The question is: how can we anticipate that reuse today, and how do we document it in a way that will still be useful later on?"

According to Amelie, there are two essential conditions. First, a building must be designed in such a way that it can be taken apart. This is called design for disassembly. Second, there is a need for good documentation. "We need to know exactly what is in a building and how it is constructed, so that this information reaches the right person when the building is modified or dismantled."

New construction or renovation

Whether it's new construction or renovation, the starting point is different. "With new construction, we can start from scratch. Then we can very consciously determine what information we want to pass on to the next generation." With renovation, the challenge is different: "Then you look at what is already there, what is missing and how you can build on existing information, so that at the end of its life cycle, you end up at the same level as new construction."

According to Amelie, this way of thinking is still far from standard practice today. "It is often not a priority. That is precisely why I see my PhD as a side step: to investigate this further and hopefully put it into practice."

Not a new idea

According to Amélie, designing for disassembly is not a new concept. "We used to build that way all the time. It was only later that we started connecting materials in a way that is difficult or impossible to reverse." The renewed focus on demountable construction received a significant boost in 2020 with an ISO standard that lays down the principles of adaptable and demountable construction. "This also explicitly emphasises the importance of documentation. And that is precisely where my focus lies: if we design for disassembly, how do we ensure that this knowledge is not lost?"

A materials passport as a collective tool

For Amélie, a materials passport is a crucial tool for structuring that documentation. "It's a way to collect information, organise it and make it accessible." Importantly, it is not an individual responsibility. "I really see it as a collaborative effort, with different parties working together."

Exactly who takes on which role is not always clear today. "My research shows that it is more of an organisational than a technical problem. It's about collaboration." She therefore looks not only at what information is needed, but also at how teams are organised and how digital tools such as BIM can support that process.

She believes that the chosen form of collaboration can play a role in this. "In a construction team, for example, parties tend to sit down together earlier and set goals in advance. That helps to clarify roles and responsibilities."

Shared responsibility, shared costs

The financial side is also complex. Who pays for drawing up and maintaining a materials passport? "My position is that it is a shared responsibility." In her research, Amelie distinguishes four key actors: the architect, the contractor, the manufacturer and the client. "They must take the initiative together."

After completion, responsibility often shifts to the client. "The team is no longer involved, but the information must be maintained until the next renovation or dismantling. You can see it as a cycle: with each new project, the materials passport is further supplemented."

Amelie also points out the importance of alternative business models. "In a functional economy, a manufacturer can remain the owner of its products and thus be responsible for the documentation and end-of-life scenario." This makes the role of manufacturers crucial. "In interviews, I often hear that materials are not designed for dismantling, or that information is missing. That is precisely why manufacturers need to be involved."

Investing for the next generation

One of the biggest obstacles remains the long term. "Those who invest today are often not the ones who reap the benefits later." We are talking about 50 years or more. "That makes it difficult to justify that investment now."

Amelie likes to draw a comparison with forestry. "Trees are planted for the next generation. The forester himself doesn't benefit from it, but he does it anyway. Why shouldn't we do the same in the construction sector?"

Research in and with practice

Because the problem is mainly organisational, Amelie actively involves people from the field in her research. She has now conducted 18 interviews with actors involved at different stages in the life cycle of a building. She also works with case studies and action research.

In the case studies, she focuses on buildings that have already been constructed and where the focus is on demountability, but where a different documentation strategy was chosen. Either highly technological, or projects that have received less attention. In this way, she investigates the different ways of working.

This action research is being conducted at Kamp C, as part of the renovation of the Infocentrum into Vonk. "For me, this is a unique opportunity to follow the process live. Not only the result, but especially the discussions along the way are valuable." She notes that even with teams that are convinced of circularity, obstacles continue to arise. "Experiencing this up close is extremely instructive."

Vonk as a learning project

For Amelie, Vonk is a particularly interesting case. "It is a renovation, with existing documentation, but also with gaps. That shows very clearly what information is important and what is often missing today." The project does not have a separate budget for a comprehensive materials passport, but that is precisely what makes it relevant. "How can we develop a 'minimum viable product' with limited resources? Something low-tech, cost-efficient, but well thought-out."

According to her, the benefit lies not in more work, but in a more conscious use of information that is often already available. "It's about showing people what valuable knowledge they have at their disposal and how they can pass it on."

No one-size-fits-all

Amélie is not working towards a single definitive solution. "I see it more as a spectrum. For each project, you have to find a balance: what really needs to be demountable, and where is that less useful? Perhaps we should focus our energy on building layers that change frequently, such as interior walls or the shell."

The same applies to digitisation. "Digital tools offer opportunities, but we must ensure that what we develop today will still be usable in decades to come." That is why she advocates a common backbone in every building: a minimum standard on which to build further, digitally or otherwise.

With her research, Amelie connects theory and practice, today and tomorrow. Vonk thus becomes not only a building, but also a living learning process — with material passports as carriers of knowledge, ready for the next generation.