The building sector is responsible for a large portion of CO2 emissions, both globally and locally. However, nature provides a finetuned system to capture CO2: photosynthesis. Since forever, plants have captured air and transformed its CO2 into carbon-molecules, trapping them to their core. To give you an idea, 1 m³ of straw stores 128 kg of CO2, which is equivalent to the emissions of an average diesel car driving a distance of 690 km.
Materials for the green economy
Interestingly, traditional building techniques have always relied on various types of plants through the ages. Today, the challenge is to adapt existing organic resources into building materials that can be implemented in modern construction. A new industry can be found innovating and booming throughout Europe. This is the opportunity to turn our cities into large carbon stores and for them to become a weapon to fight climate change.
The European Union has seized this opportunity. In the European Green Deal, bio-based insulation materials are mentioned as an effective way of insulating buildings in a way that also minimizes their embodied greenhouse gas emissions. The New European Bauhaus, which brings the Green Deal to our living spaces, even aims to create a new definition beauty, that is intrinsically sustainable.
“Bio-based": one name, a variety of products…
The term "bio-based" covers a wide range of raw materials. The best-known raw material is certainly wood, with an almost infinite number of applications, but there has been an increase in the use of faster-growing plants such as hemp, straw, and grass, along with more circular sources, such as cellulose (recycled paper pulp) or even sheep’s wool (a by-product from farming).
Both ancestral practices and modern innovation techniques have enabled us to transform these various resources into building products. The largest segment? Insulation materials. These exist in a wide variety of product compositions and range from smaller innovative solutions to mature products meeting all the regulatory requirements. Besides insulation, bio-based materials can be used in many areas: structural elements, flooring, acoustics, …
…. and many advantages
Bio-based materials bring more to the table than just their ecological footprint. Cellulose, their main component, provides an added value to every real estate project.
Bio-based materials are both breathable and hygroscopic. They are able to continuously moderate humidity levels by capturing and releasing vapour, allowing walls and partitions to “breathe”. The result ? Natural materials provide a constant and healthy indoor climate for its occupants. They also delay the condensation process on walls, helping the prevention of common problems such as mould.
When it comes to sound absorption, an important feature for materials is their porosity. Bio-based materials are naturally disposed to absorb noise in a very efficient way, increasing acoustic comfort. This is certainly to be considered for open office spaces or public facilities.
Fight against heatwaves
Climate change brings new challenges to real estate development. With more frequent heatwaves, fighting heat is a growing issue and cooling systems are very energy intensive. Bio-based materials naturally help regulating temperature. First because of their thermal insulating properties, but also thanks to their capacity to diffuse accumulated heat much slower than conventional materials. During the warmest hours of the day, bio-based materials will shield against indoor temperature increases, making it much more comfortable for occupants.
Local value chains for smaller risks
Plants grow everywhere. Organic resources can therefore lead to material production anywhere, based on a region’s natural and agricultural ecosystems. For instance, most crop residues can be used for building: straw, rice, hemp, grass, ... Each European ecosystem has the opportunity to develop its own circular economy and know-how. Bio-based materials have the advantage of being plentiful, which means scarcity will never be an issue.
Furthermore, the nature of their production (non-intensive farming, or farming by-products) are non-threatening for food sources, and as such will not compete against food-oriented agricultural markets.
Developing local, tightly-knit value chains for materials not only means creating local jobs that cannot be outsourced, but it also creates a safety net against world market distortions and far-flung resource shortages.
All in all, bio-based materials are not only a powerful tool for net-zero construction, they also bring specific added values for comfort and health. We have also demonstrated they can be a powerful tool for developing a new European circular economy, based around local ecosystems and resource efficiency. With the number of available products expanding quickly, bio-based materials have proven once again that ecological and economic impact can go hand in hand.