revalu’s curated selection for Architect@Work: a collection of low-carbon, circular, and biogenic materials showcasing innovation in construction. On view across the DACH region from May to September 2025.
At Architect@Work Zurich in May 2025, we engaged with a wide range of architects, engineers, and material specifiers interested in emerging and low-carbon materials. The following FAQ compiles the most commonly asked questions at the event, with responses based on verified manufacturer data and current research. Each section is grouped by material type.
What is the recycled content?
These boards are typically made from 100% post-consumer waste streams such as used beverage cartons, paper, and cardboard. Production generally excludes synthetic adhesives and added chemicals.
How can it be used?
Typical applications include interior partitions, ceiling finishes, cabinetry, and exterior panels. The boards are structurally strong and can support considerable load per fixing point. Some versions can also be heat-formed for curved designs.
What is the fire performance?
Fire classification typically ranges from Euroclass E to D-s1,d1. Additional layers, such as gypsum board, can enhance fire resistance. Flame retardants are generally not added during production.
Can it be painted?
Yes. Surfaces are compatible with painting, plastering, or skim-coating, allowing for integration with standard interior finishing systems.
Is it suitable for wall partitions?
Yes. These boards are often used in non-loadbearing wall partitions and provide satisfactory acoustic and mechanical performance for interior use.
What is the lifespan?
Cured mycelium components have a long service life under dry indoor conditions, typically lasting for several decades.
How long does it take to grow?
Growth cycles vary from 4 to 14 days, depending on environmental conditions and substrate choices.
Compatible materials?
Mycelium grows well on lignocellulosic residues such as straw, hemp hurds, sawdust, and seed husks. It can be combined with wood, biobased coatings, or frames for added structure.
What happens if it gets wet?
Exposure to moisture can lead to degradation. These materials should be kept dry, though they are compostable if disposal is necessary.
What are its applications?
Applications include acoustic panels, ceiling tiles, insulation, lightweight exhibition structures, packaging, and panel cores.
How is it manufactured?
A plant-based substrate is inoculated with fungal spores, grown in moulds, and heat-treated to deactivate the fungus, producing a dry, inert material.
How is growth stopped?
Heat treatment at around 70–80°C is used to halt biological activity and ensure long-term stability.
How is it made?
Hemp hurds are mixed with lime-based binders and water, shaped into blocks or panels, and cured naturally over a period of at least 30 days.
What is the mix ratio?
The mixture typically consists of 80–90% hemp by volume, with the remainder comprising mineral binders.
How long does it last?
When used correctly, hemp-lime composites mineralise over time, offering a projected lifespan exceeding 100 years.
What are typical applications?
Used as insulating blocks within timber or concrete frames, or as freestanding, non-loadbearing walls in both residential and commercial contexts.
Fire performance?
These blocks can meet high fire-resistance ratings (e.g. REI 240). They are inherently fire-resistant and do not emit toxic fumes.
Are there guidelines for use?
Yes. They must be used in conjunction with structural framing, lime-based mortars, appropriate moisture detailing, and vapour-permeable finishes.
Where does it come from?
Straw panels are made from stalks of cereal crops such as wheat, barley, and rye, often sourced post-harvest from local agricultural supply chains.
What treatments are applied?
Panels are typically heat-treated and bound using adhesives with no added formaldehyde or VOCs. Some may include mineral-based fire retardants.
Applications?
Commonly used in wall infills, roof and floor insulation, and as structural sheathing for timber or modular building systems.
Service life?
With proper detailing and protection from moisture, straw panels can last over 50 years. They are also compostable at end-of-life.
Fire performance?
Fire resistance is enhanced by the compression and density of the panels, sometimes supported by mineral additives.
What adhesives are used?
Binders are typically bio-based or PET-derived, with no use of phenol, formaldehyde, or acrylic resins.
Source material?
These boards are produced from plant residues such as flax, hemp, miscanthus, and other crop by-products, repurposed after agricultural harvesting.
What treatment is applied?
Fibres are cleaned, shredded, mixed with natural or bio-based adhesives, and hot-pressed into rigid panels. Additives like bleach or formaldehyde are not used.
Applications and durability?
Commonly used for indoor wall cladding, cabinetry, and furniture elements. While not structural, they offer moderate thermal insulation and are durable for interior applications.
Where does it come from?
The primary input is meadow grass, often collected from landscaping maintenance or roadside mowing and processed into insulation-grade fibre.
What treatments are applied?
The biomass is cleaned of sugars and proteins, then treated with natural fire retardants and antifungal agents to meet performance standards.
Applications and longevity?
Used for thermal and acoustic insulation in walls, roofs, and floors. With proper installation, the material can exceed 50 years of service life.
Can any wood be used?
Softwoods like pine, fir, cedar, and larch are preferred due to their structure and finish quality. Hardwoods may be less suited for exterior use unless specifically treated.
Is oil applied?
Yes. Natural oils are often used to seal and protect the surface, enhancing resistance to UV and water.
What is the lifespan?
With appropriate installation and maintenance, heat-treated wood products can last 50–100 years.
Why is it more durable?
The thermal modification process carbonises the surface, reducing susceptibility to rot, pests, and moisture, while improving dimensional stability.
Does it shed ash?
Heavily charred surfaces may shed slightly at first. Brushing and oiling are used to stabilise the finish.
How does it perform in rain?
Rain typically beads on the surface. When correctly treated, the material handles wet-dry cycles well without deterioration.
What is the origin of the clay?
Clay is sourced from excavated soils, often reclaimed from local or regional construction projects, and processed with minimal intervention.
What colours are available?
Pigmentation comes from the natural mineral content of the clay, typically resulting in earth tones like cream, grey, red, and brown.
What are the benefits over conventional paint?
Clay paints are free from VOCs, anti-static, moisture-buffering, and biodegradable. They can be removed and reapplied, making them suitable for circular interior design.
How does it impact indoor climate?
They regulate humidity, improve sound absorption, and provide a breathable surface that supports indoor air quality and occupant comfort.
How is the biochar made?
Biochar is produced through pyrolysis — a low-oxygen thermal decomposition process applied to biomass such as wood or crop residues.
What are the applications?
It is used in cementitious mixes to replace a portion of cement or aggregate. This improves material strength, reduces embodied emissions, and enhances carbon storage.
How does it help the environment?
Each kilogram of biochar can lock away 2–3 kg of CO₂. Once incorporated into building materials, this carbon remains sequestered long-term.
How are these materials recycled?
Plastics like PET and PVC are mechanically shredded and thermally moulded into sheets or panels. Textiles are shredded and thermobonded into boards or acoustic materials.
What are the applications?
Used across cladding, acoustic panels, interior surfaces, insulation, and furniture components.
Are non-thermal recycling methods possible?
Yes. Some processes use mechanical binding for fibre boards. For plastics, chemical recycling techniques such as PET depolymerisation are emerging as alternatives to thermal processing.
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