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Long read: Heading Towards a Biobased Transition in the Construction Sector

To stay within the Earth's planetary boundaries, biobased materials will play a crucial role in the construction sector. What is the exact impact of these biobased materials? And why will these materials play such a crucial role in the transition to sustainable construction?

To stay within the Earth's planetary boundaries, biobased materials (living materials; derived from nature) will play a crucial role in the construction sector. Therefore, it is essential for these products to be increasingly included in the National Environmental Database (Nationale Milieu Database, NMD). However, this alone is not sufficient; further steps are required for the scaling up of biobased materials throughout the construction sector. What is the exact impact of these biobased materials? And why will these materials play such a crucial role in the transition to sustainable construction?


(This article has been publishes before by Cirkelstad: https://www.cirkelstad.nl/longread-op-naar-een-biobased-omslag-in-de-bouwsector/

Breaking news: Biobased materials included in the NMD and the MIA/VAMIL list for the first time


During the Floriade Expo 2022, visitors at The Natural Pavilion had the opportunity to explore a wide range of biobased materials. The Natural Pavilion showcased 32 walls made from various biobased materials. Life Cycle Assessments (LCAs) were conducted for 8 products (with the support of Het Woningbouwatelier), and 5 of them have been added to the National Environmental Database (NMD). These materials are EcoCocon, Rawblox, Isofloc LM wall insulation, Thermofloc F wall insulation, and Ecor ply 10 mm. Furthermore, as a first, the last three materials have been included in the MIA/VAMIL list (Environmental Investment Deduction and Random Depreciation of Environmental Investments).

Characteristics of biobased materials

Biobased materials are characterized by their renewability and the ability to be locally produced. These attributes result in low environmental impact and a low MKI score. For example, Ecor grows its product (Elephant grass) between the runways at Schiphol Airport. The Elephant grass is later on transformed into sustainable wall panels, which are then used at the airport. These panels are fully recyclable and do not contain toxic materials. Therefore, the MKI is very low at 0.48, with most of the impact occurring during the production phase.

Insights from a Life Cycle Assessment (LCA)

To add their data to the NMD, producers are required to conduct a Life Cycle Assessment (LCA). An LCA provides producers and the market with sometimes surprising insights about the product. Zoë Tan,  Sustainability & Biobased Innovations expert at Hedgehog Company, conducted the LCAs for the materials added to the MIA/VAMIL list. Tan: "Isofloc and Thermofloc are both made from cellulose, which enters the Life Cycle as a secondary raw material.

Therefore, this cellulose has almost no impact. The largest environmental impact is found to come from the fire retardant, even though it only constitutes 8% of the final product."

It was also found that for both products, the transportation from the factories in Austria and Switzerland to the end users in the Netherlands had a significant impact, overshadowing the raw materials themselves or the energy consumption during the production phase.

Biobased materials Thermofloc & isofloc

Using biobased materials for a lower MPG (Environmental Performance of Buildings)

Data from the NMD is used to calculate the Environmental Performance of Buildings (MPG), which is a legal requirement for every construction project. The MPG must remain below a certain threshold (0.8 E/m2/year), and this threshold is set to decrease to 0.5 as of January 1, 2025. The MPG value is determined by summing the environmental impact of all materials in a construction project.

By using large volumes of materials with low environmental impact, the overall MPG score for the building is reduced. If more (biobased) materials with a low environmental impact are added to the NMD, designers have a wider range of choices for materialization to reduce the building's environmental impact.

The favorable environmental benefits of biobased materials call for their increased use in the construction industry. But what is needed to make this scaling up possible?

Biobased materials are still underrepresented

Biobased materials are still underrepresented in the NMD. The NMD is actively working to raise awareness of the opportunities for biobased materials and encourage manufacturers to add their environmental data to the database.  We spoke with John Drissen, project leader at the NMD, about this. Drissen: "Without data, as an industry, we cannot accurately assess the environmental impact of construction materials. We need more data, and the NMD cannot do it alone. It must be a collaboration between manufacturers, producers, suppliers, government, associations, and our users – clients, architects, and contractors. I hope we all become aware that without data, we miss crucial insights. So I call on all manufacturers: conduct an LCA and add your data to the NMD."

Subsidies available for producers

Many manufacturers are not yet familiar with the NMD or why it is advantageous for them to provide data. To make more environmental data available to the market, the NMD has initiated the "Witte Vlekken" project. Manufacturers of products with at least 50% biobased components can apply for a €2,500 subsidy to conduct an LCA and add the product to the database. Over 60 applications have already been received, and the NMD hopes that more producers will add their products to the database.

Further tightening of the environmental performance system is necessary

However, adding this environmental data to the NMD alone is not sufficient to scale up biobased materials in the construction sector. From various directions, there is a call for the tightening of the MPG and MKI (shadow cost indicator). Because as long as these requirements and others do not decrease, having more data alone serves little purpose.

The current environmental performance system, of which the NMD is a part, is considered insufficient to effectively improve the environmental performance of buildings. This system requires further development, including the determination methods, calculation rules, NMD methods, and practical application. For those interested in recommendations for improving the MPG-MKI system, they can refer to the report "Effectiever sturen op milieu-impact in de bouw" (Effectively Managing Environmental Impact in Construction).

The author of the report, Sybren Bosch, stated, "In addition to the recommendations in this article, we advise implementing an additional CO2 standard to limit CO2 emissions and environmental impact responsibly. This means that it is necessary to not only focus on the entire life cycle but also on reducing short-term environmental impact."

This view is also endorsed by various stakeholders in the construction sector: a stricter MPG alone is not enough. From various sources, there is a call for a CO2 requirement, and recently, a signed letter with over 300 signatories,was sent to Hugo de Jonge and Rob Jetten by a group of diverse parties,  urging the implementation of this requirement. This requirement will ensure that the entire construction sector focuses on CO2 emissions, bringing the achievement of climate goals much closer.

Nationally, there is already a move towards stricter MPG requirements; between January 1, 2018, and July 1, 2021, the maximum MPG value was reduced from 1.0 to 0.8. According to the Netherlands Enterprise Agency (Rijksdienst voor Ondernemend Nederland), the goal is to further reduce the MPG step by step, aiming for 0.5 by 2025 and halving it by 2030.

Imme Groet, Senior Expert Sustainable Construction: "These adaptations are essential for scaling up biobased materials. However, there is still a gap between theoretical calculations and determination methods and practical application. Ultimately, common sense should also be used in building homes, and in that regard, biobased materials, due to their low environmental impact and healthy properties, are a very logical choice."

Reach out to Imme Groet (imme@hhc.earth) or Zoë Tan (zoe@hhc.earth) if you want to gain further information on this topic.

Photographes: © Stijn Brakkee & Daria Scagliola

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