In a groundbreaking development for sustainable architecture, a residential building described by its builder as the largest hemp house in Europe has been completed in Widnau, in the Swiss canton of St. Gallen. This newly constructed residential complex, reported to have 19 apartments, stands as a testament to the potential of hempcrete as a green building material.
A Sustainable Revolution in Construction
On the surface, the building may appear to be just another modern residential block. However, a closer look reveals that the structure is far from ordinary. The Swiss construction company, Openly, has utilised hempcrete—a composite made from the woody core of the hemp plant mixed with a lime-based binder—to build the complex, reported to cover 2,600 square metres.
Additionally, according to reports, 1,500 square metres of prefabricated hemp walls were installed, showcasing the versatility of this material.
Hempcrete offers several environmental advantages, positioning it as a strong contender in the drive towards more sustainable construction methods. Unlike traditional concrete, which is notorious for its carbon footprint due to the cement content, hempcrete can be CO₂-negative over its life cycle, depending on how it is made.
In such cases, the carbon dioxide absorbed as the hemp grows, together with some that the lime binder takes up as it cures, outweighs the emissions from producing and using the material. However, a 2020 life cycle study found that some formulations, especially dense mixes containing Portland cement, can have net-positive emissions. This carbon-storage potential is particularly significant given the urgent need to reduce greenhouse gas emissions globally.
The Cost and Comfort of Green Living
While hempcrete is more environmentally friendly, it does come with a higher price tag. According to reports at the time, it was estimated to be 10 to 20 per cent more expensive than conventional concrete.
However, the benefits of living in a hempcrete house extend beyond its environmental impact. The material also contributes to a comfortable living environment, with favourable thermal insulation properties. Despite the higher costs, the demand for these eco-friendly apartments has been strong, with all units except the penthouse reported to be leased at the time of writing.
- Hempcrete’s sustainability makes it a key player in eco-friendly construction.
- The material offers benefits such as good thermal insulation, but at a higher cost.
- The success of this project in St. Gallen may inspire further use of hempcrete in Europe.
Personal Perspective
As I reflect on the emergence of what its builder calls Europe’s largest hemp house, I find it encouraging to see such innovations gaining traction. The use of hempcrete in this project not only highlights a commitment to sustainability but also paves the way for future developments in green construction.
While the higher costs may be a barrier for some, the long-term benefits of such materials could outweigh the initial investment, particularly as we continue to seek solutions to our environmental challenges.
