From Hy-Fi to Hy-Lo — Mycelium-Grown Architecture Moves From Pavilion to Production

The Material Brief

Mycelium-bound composites are produced by growing a fungal mycelial network through a substrate of agricultural waste, typically chopped corn stover, hemp hurd, wood chips, or rice straw, inside a forming mould. After the mycelium colonizes the substrate, the bound block is heat-treated to halt growth and stabilize the structure. The resulting material is biological in origin but inert in service. The most common production strains are Ganoderma lucidum and Trametes versicolor, chosen for their dense, uniform hyphal networks and their tolerance of low-cost substrates.

The relevant material properties are competitive with several established categories. Density typically falls between sixty and two hundred kilograms per cubic metre, depending on substrate compaction, which places mycelium composites in the same range as expanded polystyrene foam, balsa, and lightweight cork. Thermal conductivity sits between zero point zero four and zero point zero six watts per metre-kelvin, comparable to mineral wool insulation. Acoustic absorption coefficients in the mid-frequency range exceed those of most synthetic foams. Compressive strength is modest but sufficient for non-loadbearing applications.

The structural ceiling, for now, is the dominant constraint on adoption. Mycelium composites cannot replace concrete or structural steel. They can, and increasingly do, replace polystyrene foam, mineral wool, polyurethane acoustic panels, and lightweight infill blocks.

The Hy-Fi Reference Point

The Living, an architectural firm founded by David Benjamin, won the 2014 Young Architects Program at MoMA PS1 with a forty-foot tower assembled from approximately ten thousand mycelium-bound bricks. The bricks were produced by Ecovative Design, the New York company that had been developing mycelium production at industrial scale since 2007. Hy-Fi stood from June to September in the PS1 courtyard, was disassembled at season's end, and the bricks were composted back into the New York City greenway system.

Hy-Fi was a proof of concept for production volume, Ecovative could produce ten thousand uniform, structurally adequate bricks on a defined schedule, and a proof of concept for end-of-life disposal. It did not attempt to demonstrate code compliance, fire performance, long-term moisture stability, or any of the other tests that a permanent building requires. Those tests began in the years that followed.

What Has Passed Regulatory Testing

Three lines of regulated material now exist in commercial supply chains.

Mycelium acoustic panel product. Primarily from the Italian company MOGU, which has passed European fire-class B-s2-d0 testing, sufficient for installation in commercial offices, hotels, and public-space ceilings. MOGU acoustic tiles are specified into European commercial fit-outs at small but growing volumes.

Mycelium insulation board. The UK company Biohm has developed an insulation panel certified for non-loadbearing wall applications under UK building regulations, with documented thermal and fire performance comparable to mineral wool. Biohm's primary customer base is residential retrofit and timber-frame construction, where the material competes against synthetic insulations on embodied-carbon grounds.

Structural infill block. Ecovative produces a mycelium-bound block sized to standard masonry dimensions, intended for non-loadbearing partition walls and as insulation infill in timber-frame construction. The block has US ASTM testing data for compressive strength, thermal performance, and water absorption, and has been incorporated into several Living Building Challenge-certified residential projects.

Buildings Under Construction Right Now

A modest number of permanent commercial and residential structures incorporating mycelium components are currently in design or construction. Notable examples include several Passive House-certified residential renovations in the UK using Biohm insulation panels in retrofit wall assemblies. A handful of MOGU acoustic tile installations in European hotel and office fit-outs are documented in trade press. The Bauhaus Earth initiative, a research-and-construction consortium based in Germany, has incorporated mycelium-bound elements into several demonstration buildings exploring bio-based construction at urban scale.

In the United States, mycelium-element residential construction remains rarer and concentrated in custom builds rather than developer-scale projects. The first commercial-scale building permitted with mycelium structural elements as a significant part of its insulation envelope is reportedly under construction in upstate New York, though documentation remains sparse in the public record.

The Bottlenecks Holding Back Faster Adoption

Three constraints recur in industry discussions.

Production capacity. Ecovative's New York facility is the largest mycelium production plant in the world and produces a few tons per week, sufficient to supply hundreds of residential retrofits or a few small commercial buildings annually, but well short of what would be required to displace mineral wool from any meaningful share of the global insulation market. New facilities are under construction in the US, Europe, and India, but the production-capacity gap remains substantial.

Code uncertainty. Each regulatory jurisdiction requires its own fire, structural, and moisture testing for novel building materials. The cost of running mycelium products through every relevant code regime in every target market is a significant ongoing investment that constrains how fast new product variants can reach market.

Contractor familiarity. Mycelium composites handle and install differently from the materials they replace. The labor pool trained to specify, cut, and install them is narrow, and contractor-side adoption lags material availability.

What to Watch Next

Two developments are likely to shape the next several years. The first is the gradual maturation of code testing in the United States. Several mycelium products are reportedly in the queue for ICC Evaluation Service reports, which would substantially streamline US adoption. The second is the appearance of mycelium components in mainstream developer-scale residential and commercial construction, which has not yet happened at meaningful volume but appears to be moving from individual demonstration projects toward repeatable specification.

Whether mycelium-bound materials become a standard line item in commercial building envelopes or remain a sustainability-niche specification is, as of 2026, a question with a five-to-ten-year answer rather than a one-to-two-year one. The 2014 pavilion has put down roots.