EARTH & FIBERS. Local Technologies Earthen Composites (LoTEC). Local reuse of by-products for zero-waste building materials. Appropriate building solutions in vernacular and contemporary architecture.

This doctoral research addresses the environmental and cultural challenges of the construction sector by re-examining local materials and traditional knowledge, through scientific experimentation. Entitled EARTH & FIBERS Local Technologies Earthen Composites (LoTEC), the thesis investigates earth and vegetal-fiber composites derived from agricultural and excavation by-products as low-impact, circular, and regenerative materials for the decarbonization of the built environment. The study integrates comparative analyses of vernacular construction, experimental material testing, and architectural applications. Case studies from Europe and Latin America document the hygrothermal logic and cultural intelligence of traditional earth-and-fiber systems. Laboratory analyses characterize local raw materials (soils and vegetal residues), leading to the formulation and testing of new earthen composites. Their physical, chemical, and hygrothermal properties—including thermal conductivity, vapor permeability, acoustic absorption, and fire response—have been systematically evaluated. Medium-scale prototypes constructed and monitored under real conditions confirm their technical feasibility and architectural applicability. Results indicate that LoTEC composites display versatile hygrothermal behavior, ranging from thermal insulation to heat storage depending on mixture density and fiber composition. Produced without chemical alteration of the raw materials —only sieved soils and cut vegetal fibers—they require minimal energy for transformation from raw matter to building element. At the end of their service life, they can be rehydrated and reused without performance loss or safely reintegrated into the environment. Their permeability and moisture-buffering capacity make them particularly compatible with the vapor-open nature of historical materials, enabling effective retrofitting and improved indoor comfort while preserving architectural heritage. They also perform efficiently in new constructions based on sufficiency, circularity, and locality. Beyond technical results, the research reframes architectural sustainability within a post-growth paradigm, shifting the focus from expansion and consumption toward care, adaptation, and material responsibility. By merging traditional knowledge with scientific analysis and contemporary design, EARTH & FIBERS advances a model of architecture that minimizes extractive dependence and supports ecological and cultural regeneration, positioning earthen and vegetal-fiber materials as essential components of a decarbonized and contextually grounded built environment.