**Preface to "Fungal Architectures"**

As one of the primary consumers of environmental resources, the building industry faces unprecedented challenges in needing to reduce the environmental impact of current consumption practices. This applies to both the construction of the built environment and resource consumption during its occupation and use. Where incremental improvements to current practices can be realised, the net benefits are often far outstripped by the burgeoning demands of rapidly increasing population growth and urbanisation. Against the backdrop of this grand societal challenge, it is necessary to explore approaches that envision a paradigm shift in how materials are sourced, processed, and assembled to address the magnitude of these challenges in a truly sustainable way, and which can even provide added value.

In the European-Commission-funded *FUNGAR: Fungal Architectures* Project, we proposed to develop a structural substrate by using live fungal mycelium, to functionalise the substrate with nanoparticles and polymers to make mycelium-based electronics, implement sensorial fusion and decision making in fungal electronics, and to develop monolithic buildings from the functionalized fungal substrate. We envisaged that fungal buildings will grow, build, and repair themselves subject to the substrate supplied, adapt naturally to the environment, and will sense all that humans can sense. One of the tasks of the FUNGAR project was to scout emerging technologies and development trends surrounding the cultivation and preparation of mycelium composites.

The papers cover a wide range of subjects, including the functional modifications of mycelium with inorganic particles, modifying and assessing the mechanical properties of mycelium composites, strategies for improving the flexural behaviour of composites, beehives from fungal materials, bio-welding and the reinforcement of composites, bioreactors for fungal production, the co-production of composites by fungi and bacteria, growing large-scale mycelium structures, sound absorption by composites, and the geometrical parameterisation of fungi.

This informative compendium of the techniques, methods, and insights on growing fungal material appeals to readers from all walks of life, from high school pupils to university professors, from mathematicians, computer scientists, and engineers to chemists, from craft practitioners to industrial producers of fungal materials, and from biologists to architects and artists.
