Straw bale construction in a South American mediterranean climate

Dwellings in a Mediterranean climate such as that of Chile´s Central valley must provide comfort both during the hot days and cool nights of the summer months in addition to the cold winters. International research and previous work by the author has demonstrated that straw bale construction offers high levels of insulation and can reduce the heating demand of rural dwellings in the region. However the straw’s insulating properties must be complimented by the introduction of thermal mass either in the form of thick renders or other building elements in order to avoid problems of overheating during the summer months. To date, over 40 dwellings have been constructed in Straw Bale in Chile. This paper presents the insitu measurements of environmental comfort in a recently completed straw bale house, designed and built by students from the Universidad Andrés Bello, Universidad Austral and Universidad Diego Portales, where thermal mass has been incorporated through the use of stone floors and internal earth render. The house is situated at 1200m above sea level in the coastal range of the Chilean Central Valley with high diurnal thermal oscillation. The results are compared with simultaneous measurements of a neighbouring dwelling of typical timber construction which lacks both sufficient thermal insulation and thermal mass, and analogous measurements of physical test chambers that form a part of the author’s ongoing research program into straw bale construction in central Chil