Collaborating on scope 3: How Dura Vermeer and Isovlas drive CO₂ reduction together

Bram van Vliet, Sustainability Manager at Opens in a new tabDura Vermeer Renovation Midden West , speaks plainly about the direction of one of the Netherlands’ largest construction firms:

Since 2023, we’ve committed to a net-zero ambition: by 2050, we aim for zero emissions in our projects. That includes bringing our scope 3 emissions down to zero.

This means the company is scrutinising the materials it uses and the suppliers who provide them. One such supplier is Rogier van Mensvoort, founder of Opens in a new tabIsovlas  a company producing insulation material from flax. Isovlas supplies biobased insulation to Dura Vermeer. This partnership didn’t come easily- it required data, persuasion, and above all, persistence.

To make sustainability measurable, companies need to track their CO₂ emissions. These are divided into three scopes:

• Scope 1 covers direct emissions on your own premises. Think gas consumption or company vehicles.
• Scope 2 includes indirect emissions from purchased energy, like electricity.
• Scope 3 goes further: it includes all emissions across the entire value chain, from raw materials to waste processing. That means emissions from suppliers and subcontractors too.

Scope 3 is becoming more important in reports like the Opens in a new tabEuropean CSRD (Corporate Sustainability Reporting Directive). Large companies must know how much CO₂ is released through everything they purchase. That means they’re turning to their suppliers, including SMEs, for data on materials, production, and transport.

Van Mensvoort believed in his product from the start, but the market wasn’t ready. “We started Isovlas in 2000. To put it bluntly, it was a disaster,” Rogier recalls. “No one wanted it.” Still, he persevered. “I spent two years under the machine, trying to produce something that resembled insulation material.”

Today, Isovlas supplies many major construction firms not just for sustainability reasons, but also for technical performance. “We’ve never had a complaint about internal condensation, which is a common issue with other materials and can lead to moisture damage and mold.” Rogier’s tenacity ultimately paid off.

For Dura Vermeer, CO₂ reduction is now a strategic priority.

We are fully focused on reducing emissions from materials. That is where our biggest scope 3 impact lies.

- says Bram.

"As of this year, we use only biobased materials in renovations unless absolutely unavoidable." The ambition is bold: by 2030, emissions must be halved compared to 2022. This shift demands better decisions earlier in the process. "We want to steer material choices. The earlier we have CO₂ data in the process, the better decisions we can make."

Dura Vermeer uses the BCI tool (Building Circularity Index), which uses data from Opens in a new tabthe National Environmental Database (NMD) in its calculations. "For every project, we run a BCI calculation. It helps us report, but also optimise," explains Bram.

Filling in such a calculation requires precision. "You need to know exactly how each material is composed. It takes time at first, but it’s essential to understand your current impact and where you can improve."

So what data do you actually need?  "We need CO₂ emissions data for the entire lifecycle," says Bram. "We also focus on the CO₂ storage capacity of materials. That’s becoming increasingly important in tenders." He shares a recent example: "We compared the CO₂ storage of sustainable materials like Isovlas with traditional ones. That gave us a strong, content-driven story the client could act on."

Dura Vermeer is actively looking at CO₂ storage in materials a growing factor in public tenders.

Bram notes that some traditional materials still score relatively well in the NMD. But once you factor in CO₂ storage, the picture changes. "It’s not just about numbers. I believe in the value of natural materials. They store CO₂, have lower environmental impact, and contribute to healthier indoor climates."

Isovlas is well-prepared for the growing demand for data transparency.

We include the Milieukostenindicator(MKI) score (also known as Environmental Cost Indicator) and CO₂ storage per square metre in our price list.

- says Rogier.

“I can send Bram a detailed overview of the CO₂ content instantly. After all these years, we know the numbers by heart. That helps him and other builders use our product effectively.”

Having clear data on MKI scores and CO₂ storage per m² supports clients in reporting and tendering processes.

Moreover, all Isovlas products are listed in the National Environmental Database (NMD).
“The fact that their product is in the NMD means I can immediately include it in our reports,” Bram adds. “That’s a huge advantage.” It also strengthens tender submissions. “In a recent tender, circularity and CO₂ reduction were explicitly weighted. You don’t just calculate the financials—you need to justify your material choices. With Isovlas’ data, we could do that convincingly. It was genuinely appreciated.”

This collaboration isn’t just about emissions data, but also about trust, accessibility, and shared commitment. "You can just call each other and get an immediate answer. That matters," says Bram.

Rogier agrees:

Our experience is mostly about people. If someone within an organization is enthusiastic, things start moving. And vice versa, if we trust a contractor, we’re happy to invest time.

For Bram, it’s crucial that suppliers understand what’s needed.

It helps enormously when a manufacturer has their data in order. But it helps even more when they think along with us about applications, combinations with other materials, and alternatives in complex situations.

Both leaders emphasize that this isn’t just about sustainability goals it’s also about delivering quality. "We have never had a complaint about internal condensation," Rogier notes.

“And I’m sure it’s not always applied exactly as per our guidelines. That says something.” He highlights the underestimated risks of traditional insulation, especially in retrofit projects. “With flax, you’re physically on solid ground. You’re essentially mitigating risks upfront. That’s often decisive for housing corporations.”

Bram agrees. “For residents, it makes a real difference. Sound insulation improves, air quality gets better, and you can build vapor-open. That matters, especially when people live there for years.” Flexibility in renovation is another key benefit. “With Isovlas, we can insulate now and replace the roof in ten years. That avoids double work and enables phased sustainability improvements.”

Both parties see the tangible impact of their sustainable collaboration. "It gives us confidence that it’s a proven product. And it helps them that we use it," says Bram. "If we can name the top 10 contractors in the Netherlands and link them to projects, that builds trust. And as more contractors adopt it, we can scale, reduce costs, and make the product more accessible,"  Rogier adds.

This synergy is exactly what the construction sector needs, Bram concludes: Sustainability isn’t a solo sport. These examples show how it can work: with openness, trust, and a shared goal.”

Sustainability isn’t a standalone challenge, it’s embedded across entire value chains. So the solution must be too. ING brings together people from different sectors, products, and business lines. Not silos, but collaboration across the chain. That’s how we offer end-to-end solutions and how we aim to accelerate the sustainable transition and seize the opportunities it brings.