Since ancient times, raw earth has been used worldwide as a construction material. Today, it is well known for its good environmental properties of recyclability and low embodied energy along the production process. Earthen walls regulate the interior temperature of the buildings, providing comfortable temperatures with a very low carbon footprint. As a result of those advantages, earthen building techniques have been revived and used for contemporary architecture. The aim of this paper is to review the state of the art about the thermal behaviour of earthen building, including all the monitoring and simulation analysis of real earthen constructions up to now. The paper presents the different earthen techniques known nowadays, analysing the most important thermal parameters and the thermal comfort achieved with each technique. Regardless the wide differences among the analyzed cases, the authors conclude that earth building is a suitable solution in hot and arid climates, since it preserves the indoor temperature within the thermal comfort limits most part of the time without any active system.

This study presents a comprehensive bibliometric analysis of the earthen architecture and construction scientific literature production at present, analysing the historical evolution, research patterns and trends and the investigation of the different existing earthen building technologies. Utilising the SCOPUS database, this study analysed 3804 documents published between 1968 and 2023, with an annual growth of 16.92% since the year 2001. Key findings include the identification of top authors, institutions and collaborative networks, the co-citation analysis and the main keyword analysis and classification into different clusters. Regarding the building technologies, the results indicate a prevalence of research on vernacular earthen building techniques, mainly rammed earth and adobe masonry. Nevertheless, a growing interest in innovative methods using earth-based materials can be spotted. The bibliometric analysis identifies the development of the academic interest and emphasises the importance of interdisciplinary collaboration and the need for international recognition of earthen buildings. Future research should continue to explore the environmental benefits of using earthen materials, the development of earthen building techniques and systems in modern industry and the preservation of the architectural heritage and vernacular knowledge of contemporary technology.

Nearly 30% of humanity lives in earthen dwellings. Earthbag is a sustainable, cheap, feasible and comfortable option for emergency housing. A comparative monitoring-simulation analysis of the hygrothermal behavior of an Earthbag dwelling in Mediterranean continental climate, designed under bioclimatic criteria, is presented. The dome shape Earthbag dwelling has a net floor area of 7.07 m², a glass door facing south and two confronted windows in the east and west facades. A numerical model (EnergyPlus v8.8) was designed for comparison. Twenty-four hour cross ventilation, night cross ventilation, and no ventilation in free floating mode and a controlled indoor temperature were the tested scenarios. Comparisons between experimental data and simulation show a good match in temperature behavior for the scenarios studied. Reductions of 90% in summer and 88% in winter, in the interior thermal amplitude with respect to exterior temperatures are found. Position of the glazed openings was fundamental in the direct solar gains, contributing to the increase of temperature in 1.31 °C in winter and 1.37 °C in the equinox. Night ventilation in the summer period had a good performance as a passive system. Passive solar gains made a reduction of heating energy consumption of 2.3% in winter and 8.9% in equinox.