Bio-based building: using natural materials to reduce emissions

The majority of buildings worldwide are built of mainly concrete and steel. However, production of these materials generates a lot of CO2, contributing to climate change. Instead, we can build with renewable bio-based building materials such as wood, thatch, cork, straw, (loamy) clay, flax, cotton and coconut. In addition to bio-based materials being renewable, these materials capture CO2 in buildings for longer periods of time.

Still little use

Bio-based construction is not applied often in the Netherlands. In 2022, about two percent of the buildings were made of wood, and only 0.1 percent made of other bio-based materials. Professionals within the building industry are often unaware of the environmental performance of these materials. While the amount of bio-based insulation materials, such as flax or hemp fibre replacing glass wool, has increased somewhat in recent years, specific requirements in the tender procedure of construction projects could accelerate their usage.

More knowledge

To raise awareness of these building materials, the researchers created a Bio-based Building Materials Catalogue, commissioned by the Ministry of Economic Affairs and Climate. It contains all the bio-based building materials currently on the market, with practical applications. The catalogue was first published in 2012 and updated in 2019. The 2019 version has been downloaded 7,500 times from the website, clearly indicating an interest in the topic.

Calculating environmental performance

Architects and project developers can calculate the environmental performance of materials in a building using the National Environmental Database (NMD). The database contains many examples of conventional building materials but only a few bio-based materials. So, WUR researchers are working on the Bio-based-in-NMD project, which aims to introduce 13 bio-based building materials into the NMD, including varieties of wood, lime hemp, mycelium, bamboo, and wool. Another aim of the project is to develop a method to calculate the environmental impact, particularly regarding CO2, of building materials throughout their service life. If these materials are incorporated into official databases and the CO2 impacts becomes clear, more architects may work with these materials. Since architects largely determine the materials of a building, the benefits of building with bio-based materials must become more widely known.

Developing bio-based materials

Currently, bio-based building materials are often more expensive than the fossil-fuel and mineral-derived variants because they are only available on a small scale. WUR researchers are also developing production chains and supporting certification processes to increase the application of bio-based materials. This includes creating new building products, such as bio-based asphalt and construction panels and techniques for recycling cement. In this way, WUR is working towards a climate-proof future.