Lagemaat is a Dutch pioneer in circular construction, specializing in the careful dismantling, recovery, and reuse of building materials at scale. This winter, BUILD traveled to the Netherlands to visit their offices and operations, where reuse is treated not as an ideal, but as a functioning industry. We sat down with Arend van de Beek and Justin Houtman to discuss how Lagemaat is building the logistics, expertise, and market infrastructure needed to make material reuse a practical part of contemporary construction.

How did Lagemaat get its start?

Arend van de Beek: Lagemaat began as a civil engineering and demolition company with asbestos removal in its portfolio. Nowadays, we are a top five demolition company in the Netherlands and number one in asbestos. That work gave the company a stable foundation.

Justin Houtman: The asbestos sector provided financial stability early on. And that stability allowed the company to start exploring new approaches, especially around circularity, before much of the industry was ready.

What pushed the company into circular construction?

AvdB: Interestingly, it started with regulation. In 2004, it was our wish to maximize local building permits, and we were required to present proof that the company understood what it was doing and that development could be balanced with nature. When Lagemaat developed the site for its own headquarters, the permit plan was built around maximizing ecological value while still supporting commercial activity. That was really the beginning of a different mindset.

Did circularity begin as research, or as a business model?

AvdB: The primary driver was always the business model. The company was founded in 1977, and even then, the founder was already asking: What can we do with demolition waste? At the time, demolition material was simply treated as waste, but he wanted to treat it better and find ways to reuse it. Then around 2010, the next generation took over and they asked: What are we going to do with this company? Growth alone wasn’t the goal. Doing business the right way was. So they developed a long-term plan: balancing commercial success with nature and paving the way for a more responsible form of construction.

What differentiated Lagemaat from other demolition and deconstruction firms?

JH: The difference is that we don’t just talk about circularity—we do it. We’re able to put it into action.

AvdB: And importantly, it’s profitable over time. Between 2000 and 2015, the demolition sector grew quickly, and Lagemaat decided that part of the profits would go directly into research and development around circularity and inclusion. They essentially said: Let’s invest ten percent of what we earn into doing this right, and if it fails, at least we tried.

Was it difficult to convince early clients?

AvdB: In the beginning, clients didn’t even realize circularity was happening—we simply did it.
We asked for more time, because careful disassembly takes longer, but we didn’t ask for more money. Those early projects cost the company hundreds of thousands of euros, but the leadership believed it was necessary. That raised the obvious next question: How do we speed this up? That’s when we began focusing seriously on material passports.

Explain material passports and why they matter.

AvdB: A material passport is essentially a digital inventory of what exists inside a building—what materials and components are there, what can be reused, and how. At first, I was skeptical. You can count doors and sinks, but what is the value of a second-hand extinguisher? Or a door that’s the wrong size? What struck me is that most passports focused on interior layers rather than the structure.

Talk more about the layers of a building.

AvdB: This concept comes from Stuart Brand, the author of How Buildings Learn. He describes buildings as composed of layers that change at different speeds over time. He breaks buildings down into six layers: the site, the structure, the skin, the services, the space plan, and the stuff inside. Most circular thinking was focused on the innermost layers. But those layers are only a small fraction of the building, and this led us to a number of realizations.

JH: The inside of a building is only about 14% of the total components. The majority are the structure and the skin. That’s where the initial carbon impact is. Circularity isn’t built on counting sinks. It’s built on reusing the heavy materials.

Explain that further.

AvdB: These realizations led our primary focus away from the inner 14%, and toward the structural 80%.
Circularity, for me, rests on three foundations:
• reducing waste
• reducing raw material use
• reducing CO₂ emissions
When we began doing what’s called chain analysis—tracking the carbon and material impact of construction across the supply chain—we focused on steel and prefab concrete.
This also connects to Dutch certification systems like the CO₂ Performance Ladder, which benchmarks companies based on measurable carbon reduction. And when you look at the numbers, the value becomes undeniable.

What is the timeframe to produce a material passport?

AvdB: Within a few years, we were able to create a material passport for a 10,000-square-meter building in about four hours. In that time, we know exactly how many toilets, sinks, doors—everything. That speed depends entirely on technology: scanning, software, and digital modeling.

Do you create passports for every demolition project?

AvdB: No. Many demolition projects are industrial work—bare structures. In those cases, you don’t need a full passport. You need rough tonnage: how much brick, how much steel. The passport becomes essential when the goal is reuse at a higher level.

How do you document materials that are concealed, like plaster, stucco, and layered assemblies?

JH: We use laser scans, and we do them multiple times. We scan once when the ceiling is still in, again when it’s removed, and again after services are stripped out. So you’re essentially capturing the building layer by layer.

Explain the process and benefits of reducing construction waste.

AvdB: If I remove a one-ton steel beam and reuse it as a beam, three things happen. First, it doesn’t become waste. Normally it would be cut up and turned into scrap. Second, in the new building, I don’t need to extract raw material to make a replacement (let’s say 1,700 kg, of which 700kgs are waste again). Third, because the steel isn’t remelted or recast, I avoid roughly 1,600 kilograms of CO₂. So reuse saves waste, raw materials, and carbon—at the same time. The same logic applies to concrete, and even glass.

Do you sell harvested materials on the open market?

AvdB: We mostly use these materials ourselves. That’s why we had to become a building company. We sell the realized projects, and we do so competitively compared to new construction.

Does the concrete industry feel threatened by reuse?

AvdB: The concrete industry is ambiguous about this. On one hand, they see new opportunities, and they’re proud when you tell them hollow-core slabs are very circular. It’s actually one of my favorite circular materials. We’re building a structure here using concrete slabs that are 35 years old. They were tested and inspected, and we had a 100% harvesting score—not one slab was damaged. Transport and storage are where things can go wrong, but the slabs themselves perform extremely well.

What does it mean to have a 100% harvesting score?

AvdB: When we tested them, they were about 25% stronger than the original. That’s partly because concrete continues to harden over decades. And because these slabs are industrial products, made in a controlled way, the reinforcement doesn’t deteriorate. A hollow-core slab after 35 years can look like it came out of the factory yesterday.

What is the estimated lifespan of prefabricated concrete elements?

AvdB: We’re convinced that if they’re made correctly, they can last at least 1,000 years.
We don’t see deterioration in the concrete if the reinforcement is minimal and well protected. The lifespan is extraordinary. And in second-hand use, you avoid producing new CO₂ entirely.

Tell me about the pilot project you built here on the Lagemaat site.

JH: The pilot is affiliated with ReCreate, which is a European Horizon 2020 research program focused on reusing structural building elements at scale. The pilot here was essentially a mock-up to test the structural connections for a larger commercial building. It’s only two layers and the full structure will be eight—but it allows us to test what works, what can be more efficient, and what needs refinement before the full project goes up.

So, the goal is not just demountable buildings, but remountable ones?

AvdB: Exactly. Anything can be demolished and even disassembled. But the real shift is designing systems that are remountable—so components can come out intact and go directly into a new building without loss of quality. That is the core of circular construction.

How is the process being documented and shared?

AvdB: We work closely with technical universities across Europe, and we want knowledge to flow into education at multiple levels. We think of it across three tiers:
• The university level, where scientific proof is developed
• The applied sciences, where procedures are formed
• Vocational education, where the work is executed on-site
All three levels have to work together if circular construction is going to become standard practice.

Looking back, what was the biggest risk in pursuing this path?

AvdB: Certification. The key question was: Can you prove scientifically that reuse is reliable, permit-worthy, and insurable? If you can’t get permits or insurance, then you’ve built something that cannot exist in the real market. That’s where ReCreate helped enormously. If we had to do all the testing alone, it would only apply to our own projects. But we want this to become industry standard.

So, ReCreate founded a shared knowledge pool?

AvdB: Yes, we stepped into the program and asked: can our building become part of your research? We said: we’re going to build an eight-story building, and that surprised them. They were impressed by the scale.

How do you balance competitive advantage with sharing knowledge?

JH: The advantage is that we evolve with every project. The first one is difficult, but the next gets easier. Other companies still have to start from the beginning.

AvdB: We’re in what’s sometimes called the blue ocean phase—a new market space where there’s little competition because most firms don’t yet believe this is viable. It’s similar to Tesla early on. They didn’t keep electric knowledge secret. Most competitors simply didn’t believe in the business model. Other demolition companies still say: We’ll never build complete buildings. Meanwhile, Lagemaat is now building a 75-million-euro theatre project as the main contractor, with about 80% of the materials already on site.

What are the hardest physical challenges with concrete reuse?

JH: Transportation is a major challenge. These elements are heavy and oversized. You need specialized transport, special equipment, and careful protocols for unloading and storage. That’s why we’re working to digitalize the storage facility—so we know exactly where each element is, how it should be stored, and in what order it will be needed.

The term “legolizing” is noted in Lagemaat’s literature with reference to buildings. What does this mean?

AvdB: Legolizing a building is our term for translating the donor building into a full digital model. We take the original building and put it into Building Information Modeling (BIM), often using software like Revit. Every component gets a unique identifier. So instead of seeing demolition as rubble, we see a catalog of elements: beams, slabs, façade panels, and each one is traceable.

How is this changing the architecture profession?

JH: Normally, an architect begins with a sketch and adds detail later. We begin with the elements we already have. You’re designing with existing pieces, like a kit of parts.

AvdB: We call it a block box—a virtual inventory of all available components. The architect still shapes the building, but they are doing so from the parts contained in this block box. This method also requires the engineer to work in parallel, because the structure is not an afterthought.

Is there a particular project that changed financial perception of circularity?

AvdB: People assume circularity is nice, but too expensive. One of the best examples is a courthouse designed by the Dutch architecture firm cepezed as a true kit of parts. The building was meant to be used for just five years. It was the most expensive of three bids at first, but once its residual value was certified and deducted, it became the cheapest option. The government ended up paying the lowest price. The user (Justice department) had a full-scaled quality building instead of ‘container-like’ housing. After the building had served its purpose, Lagemaat bought it. Because the building was demountable, we disassembled it and resold the parts at a profit. At the same time, the government got a building with lower CO₂ and at no extra cost. So, I don’t see where the added price is—I only see winners.

Arend van de Beek is a Director at Lagemaat, where he leads the company’s circularity program and strategic development. His work focuses on digital transformation, circular workflows, and embedding residual value thinking into both demolition and new construction processes. He studied Business Informatics at Windesheim University of Applied Sciences in Zwolle, the Netherlands, and founded his first company in 1989, expanding it while completing his degree. Prior to joining Lagemaat, he was an IT entrepreneur — experience that now informs his systems-driven approach to circular construction.

Justin Houtman is a BIM Integration Engineer at Lagemaat, where he develops digital workflows that support circular construction and material reuse. His work focuses on integrating BIM with deconstruction planning, material tracking, and reuse logistics to improve data transparency and efficiency. He studied Building Construction Technology at Deltion College in the Netherlands, grounding his digital expertise in hands-on construction knowledge.