Architectural Design V-IX: Sandstone (E.Mosayebi)

Abstract

We engage with sandstone, its extraction and processing methods, and its role as a load-bearing material within structural and constructive systems. In the cities of Fribourg and St. Gallen, we develop residential floor plans and explore the architectural qualities and aesthetic potentials that emerge from an examination of material processes and temporal cycles.

Objective

MATERIAL AND CONSTRUCTION Students acquire knowledge about sandstone and its extraction processes. Based on this knowledge, they learn to develop the building as a structural-constructive system that reflects today's natural stone extraction processes. FLOOR PLAN AND CONTEXT Students learn to combine the aforementioned strands into a coherent, experimental floor plan for residential use. We focus on embedding the building in the local context: students learn to integrate their building into the urban fabric of selected sites in the cities of Fribourg and St. Gallen. NARRATIVE AND PRESENTATION In search of narratives of time, students learn to establish their projects in a multidimensional way. With the perspective of time, we examine rhythms of use, component cycles and the ageing of materials. The developed narrative helps to shape the project into a consistent whole and present it to others.

Content

Bernese Molasse, Bollinger sandstone, Basel Buntsandstein, and Molasse de Villarlod are identity-forming natural stones from which entire cities have been built. This relatively soft, compact, and homogeneous stone originated through the consolidation of minute sand grains derived from weathered rock fragments and transported by water. Depending on the composition of the sand, sandstone appears yellowish, greyish, reddish, or bluish, giving cities their distinctive chromatic character. For centuries, it has been used as a noble building stone for façades, plinths, and staircases, not least because of its excellent workability for stonemasons. Some sandstones are sensitive to climatic conditions: rain and wind cause erosion, requiring continuous maintenance and repair. Today, sandstone is rarely used in new construction, having been largely displaced by industrialized building materials, despite its structural capacity and durability. At the beginning of the semester, students will document active sandstone quarries in Switzerland. The investigations focus on geological formation, varying sandstone qualities, extraction techniques, block production, and the processing of raw material into building stone. Particular attention is paid to material-inherent properties such as stratification, porosity, compressive strength, and weathering behaviour. The design sites for the semester are Fribourg and St. Gallen, two cities whose architectural cultures are fundamentally shaped by sandstone. Against the backdrop of increasing demand for housing and questions of urban densification, students will design adaptable residential buildings that reinterpret sandstone as a constructive and spatial principle—from quarry to detail, structure, and urban placement, to experimental floor plans. Special emphasis is placed on the tectonics of the building and their expression in the façade. Architecture and time form the conceptual framework of the semester. Students examine processes of ageing, repairability, and renewal cycles of sandstone building components, as well as the transformation of space and use across different temporal scales. The simultaneity of the non-simultaneous constitutes the overarching design framework. The Sandstone Semester is part of our ongoing series on building with natural stone. Following limestone, this semester is dedicated to sandstone; the next semester will focus on granite and gneiss. In workshops, students will produce samples of sandstone plaster and construct stone structural models at a scale of 1:20. Experimental visualizations will be developed in collaboration with the artist Taiyo Onorato. An excursion to St. Gallen and to the Bärlocher quarry is planned for the first week. Guests: Jürg Conzett, Marlène Leroux, Steve Webb, Christian Bärlocher, Charlotte Truwant, Robert Flatt In cooperation with Prof. Dr. Jacqueline Pauli and artist Taiyo Onorato

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