When we talk about biochar in construction, someone who has wobbled his way on the internet, has heard of some really cool stuff Ithaka Institute has been doing in this domain. There are a few scattered research positions open in this space too.

It would, however, be incorrect to say that biochar in construction is confined to laboratories and pilot projects. True there are pilots and ongoing research, but a handful have found industrial acceptance. Companies like Carbo Culture, Made of Air (Germany), and NovoCarbo (Germany) supply biochar for construction composites. Europe (especially Germany, Switzerland, and Austria) has commercial projects where biochar is mixed into lime plaster, mortar, and concrete. Biochar plasters and wall panels are well used in eco-housing projects in Europe,like Switzerland’s Haus der Zukunft. Made of Air has produced façade panels incorporating biochar composites, actually installed on buildings, including in Berlin and Munich.
EU is leading this with this slowly taking over North America and Asia, India included. Pilots are shrooming up in India and how, with leading research institutes involved in the grind.


People ask why? Why is biochar in construction becoming such an architectural fad? Well,Biochar demonstrates a wide range of functional benefits when incorporated into construction materials. Its thermal insulation capacity arises from its highly porous, low-density structure, which traps air within its micro- and nanopores, reducing heat transfer much like modern foams. When blended into lime or clay plasters at 50–80% by volume, biochar can achieve thermal conductivity values similar to polystyrene or expanded clay, while simultaneously reducing material weight and lowering structural stress on walls and foundations. Beyond insulation, biochar also functions as a natural air decontaminant: its large internal surface area and reactive surface chemistry adsorb volatile organic compounds (VOCs), aldehydes, ammonia, and sulfur oxides. In lime-based plasters, the pores can further host beneficial microbial communities capable of metabolizing these pollutants, turning walls into passive, long-term air filtration systems. At the substructural level, biochar contributes to the decontamination of earth foundations by immobilizing heavy metals and persistent organic contaminants in soils, while its moisture-buffering capacity slows capillary rise, thereby preventing dissolved pollutants from migrating into building materials. Biochar also exhibits excellent humidity regulation, capable of absorbing multiple times its own weight in water, buffering excess indoor humidity, and releasing it back under drier conditions. This passive hygroscopic function helps maintain indoor relative humidity in the healthy 45–70% range, reducing risks of mold, dust mites, and respiratory stress. A more emergent but notable property lies in its interaction with electromagnetic radiation: when produced at higher pyrolysis temperatures (>700 °C), biochar develops partially graphitic domains that increase electrical conductivity, enabling it to attenuate electromagnetic waves. Laboratory measurements indicate that biochar-based plasters can reduce electromagnetic radiation levels by 10–20 dB, offering passive shielding in residential and sensitive built environments. Collectively, these properties illustrate why biochar is increasingly recognized not only as a carbon-sequestering additive but also as a multifunctional construction material with measurable performance benefits across thermal, chemical, and electromagnetic domains

Sounds amazing right, but more altruistic and utopian than commercially profitable right? So, why will a builder want to do this? They would because it creates both cost savings over a building’s life cycle and new revenue opportunities. By partially replacing cement, perlite, or polystyrene with biochar, builders reduce reliance on expensive, carbon-intensive materials while improving strength, insulation, and moisture regulation, which lowers future energy and maintenance costs for occupants. More importantly, buildings made with biochar can be positioned as carbon-negative assets, allowing developers to tap into premium markets where ESG credentials, green building certifications, and carbon credit revenues translate into higher sale values and stronger investor interest. In a market where buyers, tenants, and financiers increasingly favor sustainable infrastructure, biochar gives builders a way to differentiate their projects, command a premium, and future-proof their business against tightening carbon regulations, all while turning agricultural waste into a value-adding, marketable material.


Coming back to the Ithaka Institute, Hans-Peter Schmidt, says “For each ton of biochar employed in buildings, one ton of CO₂ is kept out of the atmosphere.” He underscores how high-porosity biochar plasters (with up to 80% biochar replacing sand) yield exceptionally lightweight, insulating materials that also retain carbon. 

What emerges is a picture of biochar as a uniquely multifunctional construction material - one that does not simply fill gaps in building performance but actively transforms them, from climate control to air quality, from structural resilience to electromagnetic compatibility. Unlike conventional additives, biochar operates at multiple scales: its porous structure regulates humidity and thermal dynamics; its chemical stability sequesters carbon over centuries; its microstructural integrity enhances mechanical performance; and its graphitic domains interact with electromagnetic radiation to provide passive shielding. This convergence of ecological, structural, and technological functions positions biochar not as a supplementary material, but as an additive material for construction, thus aligning building science with of sustainability and resilience.

All roads lead towards sustainable architecture. Here is hoping for mass commercial adaptation of the same.