sustainability Article Seismic and Energy Renovation Measures for Sustainable Cities: A Critical Analysis of the Italian Scenario Paolo La Greca and Giuseppe Margani * ID Department of Civil Engineering and Architecture, University of Catania, Via Santa Sofia 64, 95123 Catania, Italy; paolo.lagreca@unict.it * Correspondence: margani@unict.it; Tel.: +39-095-738-2509 Received: 13 December 2017; Accepted: 15 January 2018; Published: 19 January 2018 Abstract: One of the main challenges of the twenty-first century is to increase the sustainability level of our cities. However, a town, to be considered sustainable, must, above all, be safe, particularly against natural hazards, which in Europe are mostly related to climate changes (e.g., hurricanes, floods, storms, and landslides) and seismic events (earthquakes). Unfortunately, sustainability is still not a prerogative of most European cities, especially those placed in seismic countries such as Italy, where at least 50% of the residential stock is earthquake-prone, while over 80% of the same stock is highly energy-consuming and carbon dioxide-emitting, thus contributing to trigger hazards related to climate changes. In this context, renovation actions, which combine both energy and seismic issues are strongly needed. Nevertheless, several technical, organizational and financial barriers considerably limit the real possibility to extensively undertake this kind of renovation. This study analyzes such barriers, with particular reference to the Italian scenario, suggesting and discussing possible solutions and underlining the advantages of increasing energy and seismic performances at the same time. The proposed solutions may be effectively extended to many other countries with similar socio-economic scenarios. Keywords: seismic retrofit; energy retrofit; sustainability; safety; policy measures; apartment blocks 1. Introduction Sustainability was not an explicit value until the last quarter of the 20th century; therefore, sustainability performances were not requested in the recent past. The approach has changed in connection with the intensification of climate change, environmental degradation, overconsumption of natural resources, population growth and pursuit of incessant economic rise. Today, sustainability is instead considered a fundamental quality and a prerogative in any socio-economic context. According to the definition of the 2005 United Nations World Summit, sustainability is based on three main pillars: environment, society and economy [1]. However, the social dimension, and in particular safety, has often been neglected, especially in relation to the vulnerability of the building stock. In the last years, the EU has produced big financial efforts to increase the sustainability level of our cities and, in the 2014–2020 budget, over 5% of the European Regional Development Fund has been allocated to sustainable urban development [2–4]. These resources have mainly been driven towards energy efficiency and low-carbon measures, to reduce the energy bills and the hazard risks related to climate-change (e.g., hurricanes, floods, storms, landslides, desertification, melting of glaciers and sea level rise) that may cause significant damages and life losses. Special attention has been paid to existing buildings, which are responsible Sustainability 2018, 10, 254; doi:10.3390/su10010254 www.mdpi.com/journal/sustainability