VIRTUAL Barcelona

Abstract

Earth construction uses raw substances from within and around the building site, even in urban contexts. As raw soils and geological products are combined with crop by-products and living additives to gain structural integrity, mixtures can be adapted to local geophysical and thermal environments. As finish materials, clay soils can be used in plasters and decorative wall surfaces. These techniques have a history in every part of the world as a method that integrates heritage technique, building longevity, comfort, and low environmental impact. Specifically, relief and Sgraffito techniques include layering and curving of multiple coats to form intricate patterns, mostly applied historically clays or lime-based materials. This study aims to review unfired earthen finish techniques and specifically the histories and styles of Sgraffito. As a demonstration, a design/build workshop of an earthen Sgraffito pavilion is introduced to investigate the locality of Farm to Building supply possibilities, material origins, routes, and procurement, as a function of site-specific urban metabolism. The case study pavilion uses raw soils and geological products combined with agricultural by-products and living additives for structural integrity. Its walls are constructed of blocks pressed from soil excavated from tunnels dug to expand the Paris RER rapid transit system. The plaster on the interior includes local clays and splintered straw from agricultural by-products applied in a sgraffito technique. The incised patterns reflect the material geographies of the sgraffito technique and the maps framed by those patterns derive from an analysis of trade routes associated with the pavilion’s diverse materials.