Experimental Activities and Structural Analyses for the Restoration and Re-use of the Lazzaretto Vecchio Island in Venice

The Lazzaretto Vecchio (hospital for the isolation of plague patients from 1423 to the XX c.) is an island located in the central lagoon of Venice, preserving a historical-monumental heritage of primary interest. Around the mid-nineteenth century the island was used as a military warehouse, and part of the built heritage was demolished. Restoration interventions date back to the late 1980s, the 1990s, and the first decade of 2000. With the aim of creating the “National Archaeological Museum of the Venetian Lagoon”, a masterplan was developed for the whole island including other cultural uses, eventually funded with € 11 million in 2020 (FSC 2014-20). Accordingly, in 2022 a wide investigation campaign (crack pattern survey, sonic & ultrasonic tests, borescope inspections, flat-jack tests, timber visual inspection, densitometry and humidity analyses, dendrochronology) took place, aimed at defining the structural features of the buildings. The structural analysis was then carried out, outlining in several positions – together with on-site tests outcomes – a precarious state of conservation and compromised safety conditions. Related restoration guidelines were then approved to support the definition of the detailed restoration design, currently ongoing. The paper will present the relevant site history and foreseen development, the outcomes of the investigation and structural analysis, the consequent design approach, balancing the structural safety with the required conservation issues.