Mycelium Meets Waste: A Review of Paper-Based Mycelium Composites and Digital Fabrication for Circular Biobased Building Materials

The construction industry remains one of the largest contributors to global pollution, generating approximately 40% of total waste and significantly driving resource depletion and greenhouse gas emissions. Conventional construction materials—such as Expanded Polystyrene, Gypsum board, and Fiberboard—are energy-intensive to produce, with high embodied carbon that exacerbates environmental challenges. In response, the search for sustainable alternatives has intensified, particularly those that align with circular economy principles and regenerative design practices [1-3]. Mycelium-based composites (MBCs) have emerged as a promising solution, offering a biodegradable, lightweight material that can be cultivated on a range of organic substrates. While agricultural waste has been widely explored as a substrate for MBCs, there is increasing interest in leveraging post-consumer paper and cardboard waste—an underutilized resource with significant circular potential [4-6]. Paper and cardboard waste represent the largest fraction of packaging waste in the European Union, comprising 41.1% of the total packaging waste stream. In 2020, this amounted to over 32.7 million tonnes, surpassing plastic and glass packaging waste combined. Additionally, the pulp and paper industry are a major contributor to greenhouse gas emissions, with an average carbon footprint of 950 kg CO₂-equivalent per ton of paper produced [7-8]. Repurposing paper and cardboard waste into substrates for MBCs provides a dual benefit of reducing waste and producing high-value, bio-based building materials, as also demonstrated in a master thesis using waste cardboard with sample shown in Figure.1.