Inspired by processes of growth and construction in nature, Protomycokion is a system where renewable biomass is used to fabricate sustainable building components. Fibrous by-products (recycled newspapers, agricultural residues and construction waste) are inoculated with a fungus that transforms the waste into a resilient construction material. Live pulp is 3d printed into a column that is algorithmically designed to incorporate both the requirements of the fungus and the humans end users. The haptic and acoustic properties of the material are defined and soft; both gentle and stimulating at the same time. When combined with freeform expressions derived from the design and fabrication technology, extraordinary spaces can be created. Employing 3d printing and computational design, we move into a mass-customization era, where homes can be as expressive and varied as the people that inhabit them, responsive to diverse contexts, changes of use, and cultural preferences.