Concrete is indispensable in our modern, industrialized society. Infrastructure constructions such as tunnels, bridges, and roads like the “Wiener Gürtel”, as well as residential buildings, are built from concrete. In a growing city like Vienna, new concrete structures are sprouting up everywhere. However, this progress comes at a cost: concrete, and more precisely the cement it contains, is responsible for about 7-10% of anthropogenic greenhouse gas emissions—not because the cement itself is highly CO2- intensive, but due to the enormous quantity produced of ca. 4.1 billion tons per year1 . This raises the question of whether concrete is replaceable. Can at least residential buildings, and other low bearing application (i.e., separation walls…), which are increasingly necessary, be made from a material other than concrete? Another important aspect to consider in developing cities, is the continuous expansion of the metropolitan area which produce substantial amounts of excavation materials during the construction of buildings and infrastructure facilities, such as the new subway lines in Vienna. Could there be a chance to repurpose this excavation material as a construction resource? The RecyClayCrete project aims to tackle these questions by examining the potential of utilizing locally excavated clay as a viable resource for the future of construction in Vienna. This clay concrete will be produced without cement to ensure complete recyclability on one hand, and to keep the CO2 footprint extremely low on the other hand. Clay has been used by humanity as a building material for tens of thousands of years, not only in subtropical areas but also in our Alpine region. Its advantage lies in an enormously low carbon footprint since it does not undergo an industrial process2 . However, clay is often mistakenly considered a material of the "Third World" or a low-tech material. Buildings made of clay in Central Europe date back to the year 1848 and are still in very good condition3 . A well-known example right from the heart of Vienna is the Basiliskenhaus, first mentioned in 1212, which partly consists of clay4 . Additionally, due to climate change, especially in urban areas during the summer months, there is an expectation of heat hotspots, leading to a significant increase in energy demand for cooling. This problem can be easily addressed by using clay as a building material, due to its excellent hygrothermal properties that positively impact the indoor climate without wasting additional energy on cooling5 . Already existing projects and cooperations from TU Wien (Klima Biennale Wien6 , Biofabrique Vienna: Material Assembles7 , and BasaltClayCrete) on raw earth construction from regional clay would profit from the “Stadt Wien Jubiläumsfonds”.