Whether in the construction of buildings, the extraction and transportation of raw materials or the production of building materials such as concrete, the construction industry produces enormous amounts of greenhouse gases and, according to the Federal Environment Agency, consumes more than 70% of all raw materials mined in Germany. To conserve resources and the environment in equal measure, renewable building materials such as wood, straw and hemp are becoming increasingly important. Students at the Technical University of Munich (TUM) are currently working on a building material that can be produced from regional waste materials, thus avoiding long transportation routes and greenhouse gases.

Hop residues from the region as raw material

In their search for regional raw materials suitable for use as building materials, the founding team of HopfON came across hops - more precisely, the residual materials from the harvest in the nearby Hallertau, the world's largest hop-growing region, which are not needed for brewing beer. "In addition to the ecological benefits, this also has a cost advantage," says Marlene Stechl, who is part of the founding team of HopfON alongside Matthias Steiger, Thomas Rojas Sonderegger and Mauricio Fleischer Acuña.

Material tests confirm suitability of hops as a building material

Supported by architecture professor Niklas Fanelsa, the quartet was able to carry out initial material tests in TUM's Bioregional Design Lab. It quickly became clear that the plant, which is mainly used for brewing beer, is also suitable as a building material. Similar to hemp, to which hops belong, the fibrous structure of hops provides good tensile strength, which is primarily required for acoustic panels, insulating materials and building panels. The wooden core of the plant, the so-called shives, in turn provide the necessary compressive strength. The hop material also impressed in the test in terms of thermal insulation and flammability.

Company foundation and first products planned for 2024

With its idea, the HopfON team won first place in the TUM IDEAward 2022, endowed with 15,000 euros. With the TUM Booster Grant, the team also received one-year funding of 45,000 euros and two prototyping grants from UnternehmerTUM, the Center for Entrepreneurship and Innovation at TUM. The HopfOn team plans to use the start-up capital to found a company in 2024. The quartet's aim is to create a recyclable building material that does not require artificial and poorly soluble additives. This would allow the building materials made from hops to be broken down into their components at the end of their use and reused for new products. "We are working on being able to offer a serious alternative to conventional building materials at some point," says Stechl. The students want to launch the first acoustic panels made from hops for sound insulation on the market this year.

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