25 July 2023 at 00:01
Fibers from flax and hemp can make construction a lot more environmentally friendly, researchers from ABN AMRO have concluded. For this, more of it must be cultivated, for example in Eastern Europe.
There are more crops with good properties, but few plants are usable on a large scale. “Flax and hemp are an exception to this,” the researchers write. So almost all of the plants can be used.
The fibers of flax and hemp are good for insulation boards, blow-in insulation and ceiling systems, among other things. And if construction comes to a standstill, also for animal feed, paper and textiles.
The cultivation of these plants would also contribute to environmentally friendly agriculture. The crops can store CO2 for a long time and clean the soil on which they grow. Furthermore, they are not very dependent on extra fertilizer and water.
Little space in the Netherlands for extra crops
The idea of using crops on a large scale in construction is still in its infancy. In the Netherlands there is a fight for the available space, let alone that fields can be laid out for flax and hemp just like that.
The researchers emphasize that cooperation with European countries will be necessary. In Eastern Europe, for example, there is more space and fewer rules.
Because flax and hemp take up a lot of space. “With one hectare of hemp you can insulate about one house, but if the growing season has been very wet, you need two hectares for the same house,” says Cor van Dijken of the Building for Good foundation. The insulation task facing the Netherlands requires 50,000 hectares.
Flax yields more than hemp
There are even more uncertainties surrounding the crops. Flax currently yields 2,100 to 3,700 euros per hectare per hectare, which is more than starch potatoes. Hemp yields a lot less at about 900 euros per hectare.
Also, fire safety has not yet been tested on a large scale. “There are tests that show that fiber and hemp products score well,” says ABN AMRO researcher Paul Bisschop.
If the hemp-insulated house burns down, it will certainly not make local residents high. “The THC concentration of hemp plants is much lower than that of cannabis plants,” says Bisschop.