Adstratum and substratum: the typological process of the patio-house in Caesaraugusta (Zaragoza)

This paper reconstructs the patio-house’s typological process within the walled city of Zaragoza. The hypothesis of this study is that the tissue of the walled centre of Zaragoza shows a continuous transition from the Roman domus into the patio houses following a subdivision of the original plots. Archaeological excavations in other Umayyad territories, i.e., Palmyra and Bet Shean, revealed a continuous transition from the late Roman to the Umayyad period (Raymond, 2008). Also, Caniggia (2001) interpreted the residential building types in Naples as the evolution of the Roman domus substratum. This study instead describes the territory as a historically identified organism (Strappa, Carlotti & Camiz, 2016) and by mounting the individual building surveys reconstructs the typological plan of Caesaraugusta. The surveys were done by the Spanish topographer Dionisio Casañal y Zapatero for the Geographic and Cadastral Institute of Zaragoza in 1911. The research adopts the methodological framework developed by Caniggia and Maffei (2001), and it compares the invariant characters of individual buildings to construct the typological process. The research is based on the assumption that the patio house derived from the Roman domus, which by accepting the adstratum of the Celtiberian and the Visigothic house later developed with continuity into the Umayyad patio-house.