A pioneering initiative in Extremadura, Spain, is demonstrating how industrial crops such as hemp and kenaf can transform European construction practices while revitalizing agriculture and promoting a circular bioeconomy.
Image Credit: MarginUp!
Hemp and kenaf-based construction materials support the development of sustainable products in favor of a climate-neutral economy and a reduction in GHG emissions. MarginUp! is bringing this innovation to Spain by developing a business model that stakeholders across the country and Europe can replicate, as was demonstrated in the visit of the Hungarian stakeholders.
Jerónimo González, Department Head at CICYTEX and Pilot Leader at MarginUp!
Implemented across multiple municipalities in northern Cáceres, the project Margin Up! integrates drought-resistant crops into existing rotations to address soil degradation, low organic matter, and water scarcity caused by intensive agriculture. Early results show an increase in biomass yield in rotation systems compared to monocultures, alongside improved agricultural practices for hemp cultivation.
During a visit to the Extremadura Scientific and Technological Research Centre (CICYTEX) and the Spanish Leaf Tobacco Company (CETARSA), representatives from the Hungarian Ministry of Agriculture and Hungarian companies saw the pilot sites where field trials of the crops are developed, and fibre separation processes are tested. The visit also included a visit to Cânhamor, a Portuguese company developing hemp-based construction materials by producing carbon-negative building blocks from hemp, lime, and clay. The company is considered a reference model for scalable low-carbon construction solutions in the Iberian Peninsula. Its ECOblocks illustrate how natural resources can replace conventional fossil-based materials while reducing both costs and environmental impact across the construction lifecycle.
The growing demand in the EU for truly sustainable, carbon-negative and highly performing construction materials has proven to us that our ECOblocks are not just a 'green trend', but a genuine, impactful revolution in the construction sector.
Frederico Barreiro, Commercial Director at Cânhamor
This work adds to a broader European effort to develop sustainable value chains, by integrating hemp and kenaf into existing crop rotations alongside tomatoes, maize, and peppers. These crops are particularly well suited to the region’s high temperatures and limited water availability, offering farmers a resilient and environmentally friendly alternative.
Environmental and Economic Benefits
Hemp and kenaf require up to 50% less water than traditional regional crops and grow with minimal mineral fertilizer inputs.
A considerable increase in pollinator presence has also been observed, reflecting improved biodiversity linked to the flowering period between July and September. Industrial hemp can sequester 9–15 tones of CO2 per hectare annually, comparable to a young forest in just five months of growth (according to the literature). Biomass yields of around 7 tones of dry stalks per hectare are used to produce prefabricated construction panels, replacing fossil-based materials such as polystyrene. The system follows a cascade-use model, ensuring zero waste and closing the nutrient loop by returning organic fertilizer to the fields.
At the heart of the project is a new value chain that connects sustainable agriculture with bio-based industries, using hemp and kenaf biomass for construction panels, biogas, and organic fertilizers. The collaboration of stakeholders covering the whole value chain has enabled successful testing of fiber separation processes, prototype precast hemp panels, biogas production using hemp dust in the laboratory and pilot plant and the characterization of hemp fibers. CICYTEX leads the pilot with the support of Ambienta, Modular Home, COPAL and CTAEX Technological Centre.
With countries such as France and Portugal leading advances in hemp construction, the Extremadura project is positioning Spain as an emerging leader in the field, offering a scalable model for Europe’s transition to a greener, circular economy. As interest grows across the continent, including from traditionally hemp-producing countries like Hungary, the project underscores the potential of nature-based solutions to address climate challenges while strengthening rural economies.