Hey Reader,

In June 2019 I attended a talk in Leuven. I had just moved to Belgium six months earlier. My Flemish was not great, but I went anyway.

The ZIN project was presented that evening. A massive office complex in the Brussels North district.

The architect explained what they were going to do: not demolish and rebuild from scratch, but treat the existing towers as a material bank.

The concrete would be crushed and reused. Ninety percent of the materials would stay in the loop somehow.

I still remember the thought that went through my head: why are we not always building like this?

I quit my sales job a while later to work in sustainable construction.

The Zin project was one of bold targets. It shows what’s possible when there is a client with high ambitions and the value chain of deconstruction, concrete producers, contractors and architects is working together to make it happen.

In this edition I am looking at how the sectors in Belgium and the Netherlands set targets to decarbonize concrete.

Two countries. Different answers.

Belgium and the Netherlands share a border and more or less the same language. Both countries rely on using concrete construction. A lot of it.

Both countries believe this challenge is best solved when the whole sector works together. Therefore they started the “concrete agreements” (Betonakkoord).

It's a voluntary chain commitment. Not a law, not a regulation. A shared roadmap signed by everyone involved in concrete.

They agree together on where the sector needs to go on carbon reduction and circularity, and they set targets and timelines that everyone in the chain works toward.

The model originated in the Netherlands, where the first Betonakkoord was signed in 2018. Belgium, well actually Flanders, followed with its version in late 2022.

While the core idea is the same the roadmaps and targets clearly differ.

Belgium: circularity first

The Flemish Concrete Agreement was launched in late 2022. More than 80 companies, public players and organisations signed it.

The ambition is high: 50% CO2 reduction from concrete by 2030 compared to 1990 levels, and zero CO2 per cubic meter by 2050.

There is one problem. Nobody has published what the 1990 baseline actually was. No reference number per cubic meter. Which means nobody can tell you today whether we are really on track or not.

On the circularity side, the agreement states that by 2030, all concrete released during demolition that is of sufficient quality must be reused in new concrete applications. Not downgraded to road sub-base. Back into structural use.

In a previous edition I shared how to make concrete circular if you want a deep-dive.

The ZIN project in Brussels showed the full loop working at scale even before the Flemish Concrete Agreement existed.

3,500 tonnes of A+ certified recycled aggregates. Poured back into the structural floors and slabs of the new building on the same site.

One of the more recent success stories dates to August 2024:

342 m³ of road concrete was poured at the industrial site of Bioterra in Genk. 100% of the sand was replaced with recycled sand and 20% of the gravel came from certified recycled concrete.

In parallel to the concrete agreement, there was the Living Lab Circular Concrete by Buildwise. The initiative did a great job in educating the sector, showing what’s possible, and working on normalizing circular concrete.

My employer signed the concrete agreement as well so I am following the initiative from the beginning.

Personally, I think that great progress was made especially on the circularity front as I always felt that this was the main focus.

Lately it felt like the momentum slowed a bit down and I hope that when it revives there will be more focus on the carbon reduction like they do it in the Netherlands

Netherlands: specific carbon targets

​The Dutch Betonakkoord started in 2018. The targets are super ambitious: at least 70% CO2 reduction by 2030 compared to 1990, and climate neutral where possible.

On the circularity side: 100% of all reusable concrete must be demolished and reused as high-grade material by 2030, prioritising reuse of elements first, recycling second.

What makes the Dutch agreement different is a two-tier structure and specific targets. There is a basic compliance level (”plafondwaarde”) and there is a front-runner level for producers who want to go further, faster (”koploperwaarde”).

Both are annually decreasing targets. And challenging to reach.

Concrete producers collaborate and communicate a lot about the progress they are making towards concrete agreement.

A monitoring system covers around 60 to 65% of Dutch concrete production by volume. You can actually see where the sector stands.

The Dutch concrete sector started at 334 kg/m³ in 1990 and are at 266 kg/m³ in 2023. That’s a reduction of roughly 20%.

Still a long way to go to reach the 70% reduction on scale by 2030.

Yet, it’s very promising to see that there are solutions on the market already today that meet these targets.

And to be fair: the Dutch market is known to have one of the highest usages of low carbon concrete like CEM III/B.

Front-runners in practice: VBI

Let’s take a look at an example of what the front-runners already produce today.

VBI produces prestressed precast hollow core floor slabs. They are one of the largest producers in the Dutch market. They have built their product range around the Betonakkoord’s logic.

• Their standard line, VBI Groen, is already lower carbon than conventional concrete and available at full volume.
• A step above that is VBI GroenPlus, for clients with specific carbon targets.
• At the front-runner level sits VBI GroenLab, where they are working with a fundamentally different binder.

The floor slabs are made with geopolymer concrete, a cement-free alternative that cuts CO₂ by up to 75% compared to standard concrete.

In early 2026, the first four homes in Roosendaal (Netherlands) were built using these floor slabs as part of a initiative of the TBI Group. TBI is one of the Netherlands’ largest construction groups and calls it “NEXT level casco”.

So what does this mean for you?

The supply exists. Low-carbon binders. Validated front-runner products with EPDs you can use in tenders and projects. Circular concrete with recycled content.

The supply chain exists and is ready to be challenged.

What is largely missing is the demand signal from clients.

If you are a building owner: the concrete agreement in your country is a useful reference point, even if imperfect. Ask your contractor and architects whether the concrete they are using is in line with it. Challenge them.

If you are a contractor or architect: the products exist that your clients may start asking for.

Ask for a calculation of your concrete supplier’s product carbon footprint (e.g. a LCA or EPD). Concrete suppliers typically have these information.

The Circular Concrete Center in Belgium and the Betoninnovatieloket in the Netherlands both exist to answer questions and help verifying innovative concrete mixes.

Reader, have you already worked with products that matches the concrete agreement targets?

Tip of the week Linked to this week's edition, I'll share a video that the TBI Group released linked to their "NEXT level casco" I talked about before. At the project Beekhof in Roosendaal they showcase that industrialisation and CO2-reduction can go hand in hand. I added it to a playlist of inspiring videos I showed before. ​

Disclaimer

This newsletter represents my own thinking, not that of my employer or the boards I sit on. I write it because I find the topic important not on anyone’s behalf.