Geographical and environmental conditions were two of the most important factors on the design and construction of traditional architecture. Traditional earthen architecture is found throughout the Iberian Peninsula in numerous constructive techniques and variants, most notably rammed-earth, adobe and half-timber. The varied morphology, climate, geology and culture of the Iberian Peninsula, together with its immediate surroundings, have a direct effect on the development and the properties of traditional architecture. Thus, the objective of this research is to establish the relationship between the geographical characteristics and the distribution of the earthen techniques. For that purpose, the authors of this text have carried out a thorough data collection throughout the whole of the Iberian Peninsula in order to identify the main characteristics of this architecture in each location and to produce maps featuring the locations for each technique. This mapping of numerous techniques has been compared with other thematic maps of the territory, establishing relationships between the different techniques and specific properties of a given area. These provide hypotheses on which factors encourage or hinder the use of earthen construction techniques. Moreover, the relationship of traditional architecture with geographical factors and its specific morphology on a given place has provided many design lessons for a sustainable architecture. Those lessons must be taken into account on rehabilitation works and new architecture.

Purpose: The purpose of this paper is to identify and characterise bioclimatic strategies of traditional earthen architecture in a specific territory, the Valencian region of La Serranía. These constructions were built in relation to their surrounding geography or climate through several mechanisms facing the action of solar radiation, water, wind, etc. Design/methodology/approach: The research methodology is based on a comparative analysis of selected case studies representing the constructions and typologies of traditional earthen heritage in a territory with similar geography and climate, albeit with certain zonal limitations. Findings: The results show that these constructions built with earth offer a global solution to environmental conditioning factors of the region by a series of strategies formalised at urban, architectural and constructive level, either independently or jointly. Although climate variations affect its behaviour, traditional earthen architecture seeks compactness to reach indoor comfort. Originality/value: Traditional earthen architecture is a valuable heritage in danger which has been devaluated until several years in this remote region. Therefore, prior knowledge of its bioclimatic strategies and formal constitution is essential to establishing heritage intervention criteria and proposals adapted to its geographical, socio-cultural and socio-economic context.

Learning from the sustainability of traditional architecture, as a solution to the current ecological crisis, seems more challenging in societies where a cultural imposition has occurred. In Burkina Faso, vernacular architecture has experienced a process of transformation, still in course, relying heavily on foreign resources and losing its adaptation to environmental conditions. As in other contexts, the dynamics of transformation are being examined. Joining this line of work, this research aims to explain the causes of the current local perception of traditional building techniques in Burkina Faso in order to consider how a sustainable development of its architecture would be possible. To this end, a historical analysis is conducted by reviewing the literature, consulting historical documents and collecting data during two stays in 2018. The study shows how earth has ceased to be appreciated by progressively becoming associated with “non-definitive constructions”; this perception is due to the narratives put forward by foreign agents since the end of the 19th century. The sustainable development of architecture in Burkina Faso seems to demand a return to the use of earth, local resource par excellence, but this will only be possible if the devaluation of this building material is reversed.

Earthen architecture is an essential part of the architectural and cultural heritage of the Iberian Peninsula. Both at monumental and vernacular level, this architecture has adapted to the diversity of the territory, the different geographies and climates, the variety of materials available and the cultural diversity which have led to a great wealth of constructive variants of this architecture. The RISK-Terra Project was born in this context, funded by the Spanish Ministry for Science, Innovation and Universities, aiming to contribute to the study of this heritage scientifically researching and analysing the natural, social and anthropic threats to earthen vernacular structures, as well as deterioration mechanisms and transformation dynamics currently observed in this type of architecture in the Iberian Peninsula. The research presented in this text has been carried out within the framework of the RISK-Terra Project, with the main objective of developing an analysis tool for application to any element of traditional architecture or earthen vernacular architecture, assessing the degree of vulnerability to the sudden action or continued presence of natural risks (earthquakes, floods, extreme weather events).

The constructive solutions characteristic of vernacular architecture are the result of the convergence of geographical, cultural and climatic factors that bring about constructions characterised by adaptation to their surroundings. However, at present, Spanish regulations do not contemplate the properties of traditional materials, such as those found in earthen constructions, whose great thermal inertia is ignored despite their thermal gains and compensations. Given these limitations, the purpose of this study is to assess the thermal behaviour of traditional earthen architecture adjusting to its real performance and original surroundings. This work thus examines a methodology to assess the thermal behaviour of rammed earth walls based on on-site data specifically collected in the summer in a case study located in La Serranía, a region in the northwest of the province of Valencia (Spain). The results show the evolution of exterior and interior surface temperatures of the earthen wall, quantifying its variation frequency and thermal energy transmission. Based on these data, the thermal transmittance of the wall is calculated and compared to highlight the difference from the normalised value, showing that a review of the Spanish regulations applied to earthen architecture is needed.

El creciente interés por el estudio de la arquitectura de tierra que se desarrolló en Europa a finales de los años setenta, germinó también aunque de manera más tardía en España. A la par del creciente interés por estas estructuras históricas de tierra, se incrementó también el número de proyectos de restauración llevados a cabo en estos edificios. A partir de la década de 1980, las intervenciones en arquitectura de tapia en toda la Península Ibérica fueron en aumento, por lo que estas actuaciones tienen también ya un cierto recorrido. Esta investigación analiza las intervenciones realizadas en edificios monumentales de tapia en el territorio español financiadas con fondos estales, con las lesiones afrontadas más frecuentes, los criterios de intervención adoptados en cada caso, las técnicas constructivas empleadas y los resultados obtenidos.