Earth as a building material, the challenge of a traditional material in the 21st century Case study: Farewell room for the Serrenti cemetery in Sardinia

Earth as a building material undoubtedly has a strong fascination that merges the figure of the designer with that of the builder opening up various ecological, market and design perspectives. Many buildings have been constructed using this material since ancient times, some important in terms of size and cultural value; however, it is not frequently utilized nowadays, so it is natural to ask why such a promising material is not widely used. This paper presents the synthesis of research which aims to answer this question, starting from the study of historical examples leading up to the use of this material in the 21st century. Usually building materials can satisfy certain hygrothermal and mechanical characteristics, but when it comes to earth it is impossible to find univocal parameters. This reveals an even more worrying gap at an experimental level and above all in establishing general practices that make it impossible to compare the results. In turn it is reflected in the production of legislation where difficulties occur in abandoning the well-established empirical practices and therefore making worthy updates. Through this case study, the project of a small earth building in Italy, it was possible to verify the building construction problems from the point of view of regulatory response as well. The results of the research show how little is missing for a complete regulatory validation of this building material, thus being able to expand its use by designers.