The outgoing cabinet will release 200 million euros from the Climate Fund to boost the use of bio-based building materials in the coming years. Until 2025, 25 million of this is intended to set up a market that makes these types of building materials competitive with ‘traditional’ materials such as glass and rock wool or asphalt. The remaining 175 million must then strengthen that market.
The government sees bio-based building materials as an important way to achieve sustainability goals. Crops such as hemp, elephant grass and flax do not come from the factory, but from a field. They do not emit CO2 during production, but actually store CO2 as they grow and retain them when applied. By insulating a home with shredded elephant grass instead of glass or rock wool, construction can contribute to better CO2-performance.
Growing these types of crops can also offer a solution for farmers if they want to leave more intensive livestock farming, in which the future is uncertain due to the nitrogen problem. There is no fixed market for biobased crops yet, which makes the investment too uncertain for many farmers. Planting one hectare of elephant grass costs more than three times as much as, for example, one hectare of silage maize. Moreover, it takes three years after planting before the farmer can harvest his first crop. This creates a chicken-and-egg situation: because the supply is still relatively small and uncertain, construction companies do not want to completely switch to working with fiber crops.
The government wants to break that impasse. On Wednesday, outgoing ministers Hugo de Jonge (Public Housing, CDA) and Piet Adema (Agriculture, Nature and Fisheries, Christian Union) presented a plan to have the Dutch construction sector work largely with bio-based materials in a few years. Currently, around 3 percent of building materials by weight are biobased, but this should increase to 30 percent in the next seven years.
Using fiber crops as building material is much more common abroad than in the Netherlands. “Building with stone is really part of the Dutch building tradition. Traditionally, we have a lot of clay, sand and gravel here and little forest, which means that timber construction, for example, became popular here much later than in Germany, France or Scandinavia, for example,” says program director Jan Willem of the Group of transition organization Building Balance. Van de Groep and his organization contributed to the government’s plan and have been appointed to implement it. Over the next two years, ‘chains’ between farmers and builders must be set up to create a market for biobased building materials.
How do you get a country that is so focused on ‘mineral’ construction to adopt biobased construction in just a few years? According to Van de Groep, the most important thing is that both the demand and supply of fiber crops are stimulated. More farmers have to grow the fiber crops, causing the price to drop. “If farmers cannot get rid of their harvest, they drop out in disappointment. And if builders cannot get enough biobased raw materials, they are gone too.”
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There is now two years and 25 million euros available. In the cabinet plan, the government itself is the ‘launching customer’, or the party that must ensure that bio-based building materials become common with large orders. In the case of large tenders via Rijkswaterstaat, the Central Government Real Estate Agency, ProRail or housing associations, the government can give construction companies preference when awarding the contract if they work with bio-based materials. Housing associations can also ensure that straw and hemp fiber are chosen as insulation materials through performance agreements for new-build homes.
The list of steps to be taken in the government’s plan is long. In addition to farmers and builders, banks must also contribute to financing. Money also goes to factories that process fiber crops into building materials – which are currently mainly located abroad.
Finally, confidence in fiber crops must grow among construction companies and clients. The materials must last for decades and remain just as sturdy, fireproof and mold-free in all those years – after all, the builder is held accountable if damage occurs over time due to construction errors. Work is already underway on certificates for the various biobased building materials, so that contractors can be sure that they are at least as safe as glass and rock wool.
When the market for biobased building materials is established in 2025, the government wants to strengthen it with another 175 million euros, so that there is enough supply and demand to make fiber crops the standard. “We then assume that by then the price of biobased building materials will be the same as traditional building materials – or even cheaper,” says Van de Groep.
He thinks that it will mainly require a change in mentality, and he expects less resistance from farmers than from construction. “You are essentially telling a technically specialized group of people that they have to relearn their trade, and implicitly that they have not actually done it well over the past twenty years. That is quite difficult,” says Van de Groep. “Still, I think it is necessary. Without biobased construction materials, we will not achieve any of the sustainability goals or the Paris agreements.”