All built environments are comprised of materials that are initially geological before they are architectural. The geological trade routes of building materials dictate their earthly origins: from strata, rocks, metals, minerals, chemicals, enzymes and bacteria, to politics, labor, human hands and tools. Tracking and comparing localized supply flows of materials across urban regions is therefore key to generate critical insights on material properties, labor, environmental and social life cycles, embodied carbon, and cities themselves in ways not usually accessible.

In a research project led by the Natural Materials Lab, Columbia GSAPP Assistant Professor Lola Ben-Alon and Columbia SPS Associate Professor of Professional Practice Lynnette Widder co-created the Raw Earth Sgraffito Pavilion in the Reid Hall garden to track the material trade routes and represent geographies and supply chain flows in the city of Paris and around the unique Seine working waterfront.

The Raw Earth Sgraffito project 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 was purchased from a facility in the Ile-de-France region. The mineral content of the soil creates the pigment of the structure, either pale gray or burgundy. Splintered straw from agricultural by-products is mixed into the clay for the gray base coat. The top coat is enriched with sand and mica to create a finer grain and sheen. The plaster was applied using a meticulous sgraffito technique, which involves the layering and curving of multiple coats to form intricate patterns. 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. The patterns created a series of map elements that represent the geographical analysis of material procurement to provide an immediate representations of this direct supply chain. It offered the opportunity to trace the relationship between site and hinterland along lines of supply; to consider, by comparison, the typical methods of construction used in the buildings around the workshop site; and to engage in the tactile and social experience of construction labor.

In its completed form, the pavilion serves as a seated space for conversation and viewing of the garden, while the inscriptions along the interior wall of the structure showcase a map line trace visualization to tell the story of the routes taken by materials to arrive on site. During its residency in Reid Hall’s garden, the Raw Earth Sgraffito Pavilion will evolve. The shapes will transform: corners will round, plaster will abrade, erosion from water and frost will begin to appear, patterns and geometry will change. Time, use, climate: these are all parts of architecture that the Raw Earth Sgraffito Pavilion can make explicit through its patina. It can also invite interventions, passing on authorship to new sets of hands. At the end of its life, the components can be returned, simply by crushing and dissipation, as nutritious compounds to the soil from which they came.

The construction of the pavilion further fostered knowledge exchange through collaborative activities, bringing together contractors, builders, designers, students, scholars, and material enthusiasts and culminating in discussions of and hands-on engagement with the building techniques. The compressed earth block “body” of the installation was constructed by Les Batisseuses, a social enterprise that engages new immigrants to teach them techniques for building with earthen material. Wood work for the pavilion, including the tricky interface between masonry and timber on the bench and roof, was completed by Patagonia, a team of craftsmen from South America. Students from two Columbia programs at Reid Hall – GSAPP’s Paris New York program and GSAS’s Masters in History and Literature – collaborated on the sgraffito. Their efforts made it possible to transfer and incise the mapped lines in the brief time during which the fresh plaster had the perfect consistency. The plaster was then finished with eight coats of raw flaxseed oil over the course of a ten-day period to improve its longevity.