Enhancing Thermal Transmittance in Peruvian Meso-Andean Housing with Local Organic Fiber Thermal Insulation

Peru has 23 cities with over 10,000 inhabitants located above 3,000 meters above sea level, 20 of which are situated within the meso-Andean range (3,000–4,000 meters). Cold-related illnesses and fatalities are frequently reported in these regions during winter. Despite this, thermal insulation is rarely implemented in housing. Current Peruvian building regulations do not mandate insulation, and the maximum allowable U-values are comparatively high for regions with similar minimum temperatures. According to existing Peruvian building standards, for altitudes below 3,500 meters above sea level, the maximum allowable thermal transmittance values can be met without incorporating insulation. However, at higher altitudes, adding a 6 cm layer of plant-fiber insulation to the typical opaque enclosures of local dwellings would be sufficient to meet regulatory requirements. This study highlights the need for a reassessment of Peru’s maximum allowable thermal transmittance values, which are significantly higher than those established in countries with similar minimum temperatures. Specifically, these values are 4 to 9 times higher for walls, 2 to 4 times higher for roofs, and 2.5 to 6 times higher for floors. This study underscores the critical role of wall insulation in improving thermal conditions in high-altitude Peruvian housing, identifying plant-fiber-based thermal insulation as a sustainable solution.