For a long time, building sustainability was primarily associated with energy efficiency—lower heating costs, efficient engineering systems, and better thermal insulation. However, as Europe moves toward a climate-neutral building stock, more attention is being paid to embodied carbon: the climate impact that occurs during the production, transportation, and use of building materials.
Therefore, a building with a lower CO₂ footprint begins at the design stage. And this does not necessarily require changing the entire structural system. Significant potential also lies in what we barely see in the finished building—the insulation of internal partitions, acoustic walls, ceilings, and other structures.
One such solution is Gramitherm® bio-based insulation made from grass fiber, produced in Belgium. It consists of approximately 70% grass fiber, 20% recycled jute fiber, and 10% binder. According to the manufacturer’s FDES and EPD data, 1 kg of Gramitherm® sequesters about 1.5 kg of CO₂ equivalent, and 1 m² of 100 mm thick insulation at the production stage accounts for about 5.01 kg CO₂-eq.
“When designing a low-CO₂ footprint building, it is no longer enough to calculate only the energy it will consume. We must also evaluate what the building is made of. Internal partitions are very interesting here: in a larger public or commercial building, there can be thousands of square meters of them, so the choice of material is no longer a minor detail, but a part of the entire project’s CO₂ strategy,” says Saulius Semovas, CEO of Conatus.
If 10,000 m² of 100 mm Gramitherm® insulation were used in a project, according to the manufacturer’s declared A1–A3 indicator, approximately 50 tons of CO₂-eq would be sequestered in the production stage balance. This illustrates how many seemingly small design decisions can add up to a tangible result.
At the same time, the material performs a practical function. Gramitherm® is designed for walls, partitions, floors, ceilings, and roofs; the manufacturer emphasizes thermal and acoustic comfort, moisture regulation, and very low volatile organic compound (VOC) emissions (A+). CSTB has issued a Technical Application Document (DTA) for the Gramitherm solution.
The solution is already being used in real European educational buildings. In the Pont-Sainte-Maxence bio-based school complex in France, Gramitherm® was used in partitions. A similar solution was implemented in the Argentan school and community center project. In the Sainghin-en-Weppes kindergarten and sports facilities, as well as the Gommegnies kindergarten, the material was used in internal wall structures.
“These projects demonstrate the most important thing—bio-based insulation is no longer a laboratory idea, but a practically designed and implemented solution. When we can combine acoustic comfort, thermal properties, and a lower material CO₂ footprint in a single structure, designers gain an additional tool to achieve more ambitious building sustainability goals,” comments Gramitherm Europe.
In Lithuania, this topic is becoming particularly relevant with the growing importance of renewable organic materials and building life cycle assessment. Wooden structures are one direction, but they are not the only one. Internal partitions, acoustic structures, ceilings, roofs, and other insulation zones can also contribute to the overall project result.
“A single product will not make a building climate-neutral. However, thousands of square meters of consciously selected materials can significantly change its embodied carbon balance. Therefore, we should increasingly ask not only what the material’s thermal resistance is, but also what CO₂ balance it brings to the entire building,” says Saulius Semovas.
Sometimes the path toward a lower CO₂ footprint begins with a decision that we don’t even see in the final interior—with the material inside an internal partition.