Overcoming the Perceptual Gap: Worldwide Perceived Comfort Survey of Earthen Building Experts and Homeowners

Earthen building materials are a critical future for sustainable construction because they are locally available, minimally processed, and waste-free. However, despite their advantages, earthen materials still face challenges for comprehensive implementation. First, their technical data vary significantly, making it challenging to quantify their true performance for different climates and environmental contexts. Second, people mistakenly perceive these materials as low-tech and poor in their performance. Lastly, building codes and standards do not comprehensively represent these materials worldwide. This work identifies perceptual barriers that hold back the broader implementation of earthen materials in order to ascertain possible solutions and assess the performance of earthen buildings and perceived comfort among primary resources such as practicing professionals and people who live in earthen houses. The results of an online survey of 126 earthen building experts and homeowners are presented, providing important insights regarding a range of barriers to, and motivating factors for, the implementation of earthen materials, as well as design and thermal performance aspects of existing earthen homes. The results of the surveys show that, of the various earthen building techniques, light straw clay requires the lowest maintenance, and construction of adobe and/or clay plaster encountered the least barriers to implementation. The energy performance of existing earthen homes show that all types of earthen materials reduce the need for cooling, in all climate zones. Insulation over earthen walls was shown to increase occupants’ perceived comfort levels, but only slightly. Additional results provide significant recommendations for future research on thermal performance and comfort guidelines for earthen structures. This study contributes to the development of environmental and policy measures that could be used by policymakers by synthesizing technical and environmental data and by identifying means of improving the perception of natural building.