Architect Ángels Castellarnau relocated to Ayerbe, near Teruel, several years ago, where she established her architecture studio. The studio she leads, Edra Arquitectura km O, is taking a significant step forward by developing prefabricated materials using earth and sheep's wool to construct efficient buildings with a minimal environmental impact.
"We have a laboratory at the studio," she explained during the interview, where the materials used, particularly earth, are examined. "For instance, we conduct tests on granulometry and sedimentation. In other words, it’s essential to master the material and carry out extensive testing before using it on-site," she noted. Additionally, in some of her designs, she has employed wool – an undervalued resource that has been largely discarded or wasted for years – which serves as an excellent thermal insulator. Thus, it was only a matter of time before they developed a new building material combining wool and earth. This innovative material, called LanaTerra, is a large-format prefab that creates building façades by merging the superior thermal insulation of sheep's wool with the thermal inertia of the earth.
Decarbonised buildings by 2030
“Dry assembly speeds up construction times, optimises quality control and eliminates waste. The material adapts to any project type and scale that aims for a natural, healthy and efficient building with a low environmental impact," said Edra.
This material – a blend of earth infused with fabric fibres – is designed to meet the decarbonisation expectations currently facing the construction sector due to European regulations. The new European Building Directive will mandate the production of decarbonised buildings using natural-based materials by 2030. This is a lightweight, industrialisable material that is compatible with the timber construction systems that have gained significant traction in the sector in recent years.
The prototype parts are currently being manufactured and will be assembled in the coming months, with work already underway on the first single-family house. The system is set to be integrated into new multi-family buildings starting in 2025. Wool serves as an excellent thermal and acoustic insulator; it is also fire-resistant, moisture-regulating and exceptionally durable.
Edra is one of the few architectural studios in Spain that specialise in building with earth. One of its first projects was Castellarnau's own house, constructed in Ayerbe using locally sourced natural materials. Stone, earth and straw account for 80% of the building's weight. This innovative home won the 2016 TERRA Award, an international prize for Contemporary Raw Earth Architecture, selected from over 350 submissions worldwide.
