A groundbreaking experimental pavilion in Tallinn, Estonia, is showcasing the potential of mycelium-based insulation materials as a sustainable alternative to traditional building products. The PAKK Pavilion was developed through a collaboration between materials company Myceen and EKA PAKK, the timber research center within the Faculty of Architecture at the Estonian Academy of Arts.
The angular timber structure serves as a testing ground for innovative insulation panels made from mycelium, the root system of fungi that forms a biomaterial. This marks Myceen's first venture into building products, following their previous work creating mycelium-based pendant lampshades. The company aims to provide an eco-friendly alternative to conventional insulation materials like mineral wool and expanded polystyrene.
Myceen's specialized panels, known as mycocomposite, utilize mycelium growth as a natural binding agent for industrial waste products including sawdust and wood pulp. The growth process is carefully controlled and stopped through a specialized drying method. "Talking with architects, builders and prefab house producers around Europe has given us confidence that the material is needed in the market," explained Siim Karro, CEO and co-founder of Myceen.
The pavilion's construction showcases two ongoing research projects from EKA PAKK. The first, called Pattern Building, is an open-source modular timber construction system designed for easy disassembly, modification, and expansion based on specific requirements. The second project, sLender, is an innovative facade system that gives the pavilion its distinctive angular appearance.
For the structure itself, builders used ash dieback timber to create a cubic frame, which was then covered with timber planks. The sLender facade system was specifically developed to address concerns about "homogenization" in Estonia's aging housing stock renovations. The system features lozenge-shaped, modular timber sections designed to over-clad existing structures while providing improved insulation, balconies, elevator modules, and stair systems.
In the PAKK Pavilion, these modular components wrap around a front terrace and enclose a straight staircase leading to a roof terrace. The mycocomposite insulation panels installed within this structure will undergo comprehensive testing until the end of 2026 to evaluate their thermal performance and assess any mold risks.
Preliminary testing results have been promising, according to Killu Leet, Myceen's head of science. "Preliminary results reveal no condensation or mold risks, demonstrating excellent moisture management for our biocomposites," Leet stated. "Furthermore, measured U-values indicate superior thermal resistance compared to mineral wool under the same conditions."
The PAKK Pavilion represents part of a growing trend in architecture toward biomaterial usage. Recently, a pavilion designed by London practice Studio Weave, landscape designer Tom Massey, and furniture designer Sebastian Cox featured mycelium used to bind agricultural waste into textured facade panels. Other notable projects incorporating the biomaterial include a mycelium-insulated stage at the Glastonbury festival and a restaurant in Ukraine that uses mycelium as curtains.
This experimental structure demonstrates the potential for sustainable building materials to replace traditional options while maintaining or improving performance standards. As the construction industry seeks more environmentally friendly alternatives, projects like the PAKK Pavilion provide valuable real-world testing data for innovative biomaterials and their practical applications in modern architecture.
