Although more related to evolutionary aspects than to architecture itself, the inherent physical fragility of human beings has required, since prehistoric times, that we protect our bodies and our buildings from external elements. As an example, beginning with the primitive huts used in the earliest forms of domestic architecture, furs were employed as an exterior covering to restrict the flow of air and, consequently, regulate the interior environment.
Subsequently, we have observed an evolution that clearly shows advances in insulation techniques, going from vernacular materials such as adobe to an increase in the thickness of walls using stone or brick, finally reaching the cavity walls developed in the 19th century, which left a small air chamber between an exterior and an interior face of the wall. Its later popularization led to the introduction of insulation between both faces, a system that is widely recognized and used today and has laid the foundations for further developments in this field.
