**Stefania De Medici 1, Pasquale De Toro <sup>2</sup> and Francesca Nocca 2,\***


Received: 30 November 2019; Accepted: 22 December 2019; Published: 31 December 2019

**Abstract:** In this period of increasing urbanization, cultural heritage can play a key role to achieve sustainable development, as widely recognized by international institutions (i.e., United Nations (UN), UN Educational, Scientific and Cultural Organization (UNESCO), International Council on Monuments and Sites (ICOMOS)). In this perspective, it is necessary to operationalize the principles stated at international level and thus new approaches and tools are required. The paper aims to understand the relationships between the implementation of adaptive reuse projects and their success (or not) in terms of impacts on the buildings themselves and on the urban context. The assessment framework for evaluating the impacts of heritage conservation and rehabilitation projects is described through the analysis and comparison of two Italian case studies: the Ancient Market and the Basilica of St. Peter the Apostle, in Siracusa (Italy). Although realized both in the same place (Ortigia, the historic centre of Siracusa), during the same period and by the same architect, these two interventions have produced different results in terms of urban development. A set of indicators, deduced from recent scientific studies, has been used to analyse the different impacts on physical, cultural, social, environmental and economic systems. To understand in depth the causes of these two different results, a survey has been carried out involving experts. The proposed indicators used for the ex-post evaluation can be also adopted in other contexts and for ex ante evaluation, in order to orient the strategic design choices in cultural heritage adaptive reuse projects.

**Keywords:** adaptive reuse; building rehabilitation; cultural heritage; impact assessment
