Sustainable building materials such as clay, wood and straw have a positive climate footprint. As they grow, they absorb CO₂ and store it in the long term. Around fifty million tons of excavated material containing clay are produced in Switzerland every year, a potential that is only used to a limited extent as most of it is landfilled. If this soil could be used as a building material, the material cycle could be closed directly. Saving resources, less transportation and lower disposal costs are the result. Wood is equally sustainable. Swiss forests provide a fast-growing, robust building material that now accounts for up to seventeen percent of load-bearing structures in new buildings, particularly in urban housing construction and additions.
Prefabrication and hybrid construction
The modern rediscovery of traditional materials is based on high-tech production methods. Prefabricated modules, the targeted use of robots and the addition of natural additives allow faster and more efficient processes. Nowadays, clay can be poured into formwork as liquid clay like concrete or used as rammed earth with reinforcements for multi-storey buildings. Combining clay and wood in hybrid wall or façade elements creates sustainable and climate-friendly structures. Researchers are working on optimizing materials to make clay and straw even more efficient. For example, through natural additives such as trass lime or innovative reinforcements.
Challenges and development prospects
The market penetration of clay and straw throughout Switzerland is still low, mainly due to a lack of industrial development, insufficient standardization and high start-up costs. Wood, on the other hand, is already widely accepted, although the forestry industry is struggling with climate change. Softwoods are coming under pressure, hardwoods are gaining in importance, but need new processing technologies. At the same time, environmental standards must be ensured and biodiversity preserved in the forests so that CO₂ storage is maintained. Research projects are investigating how wood can be made more resistant to environmental influences using biological substances such as shellac or plant-based tanning agents.
Circular economy, health and acceptance
Innovative building materials offer not only ecological but also health benefits. Natural materials improve the indoor climate, reduce allergy risks and avoid pollutants. Production is often low-energy and the components can be recycled at the end of their life. Web platforms such as the “Atlas of Regenerative Materials” network companies and projects in order to increase acceptance of and confidence in bio-based buildings.
Innovation as a driver
The combination of traditional expertise, modern research and digital prefabrication creates new opportunities for sustainable construction. Only by combining natural materials, recyclable structures and ecological responsibility can the construction industry make a positive contribution to climate protection. The opportunities for this have never been better and the building material of the future lies in the soil, in the forest and in the fields of Switzerland.
