Editorial Introduction

The term “resilience”, and its panoply of derivations and conjugations, has known unusual popularity in recent times, often associated with sustainability. From a technical point of view, resilience is “the ability of a substance or object to spring back into shape; elasticity”, as per the Oxford Dictionary. In fact, the term is widely used in engineering and physics in order to describe the property of a material or system to quickly recover from a supposed condition of stress. But the first definition from the Oxford Dictionary, and apparently the most used, mainly referred to other meanings such as “the capacity to recover quickly from difficulties; toughness”. Therefore, resilience could be associated not only to physical properties, but virtually extended also to complex systems such as the economy, political institutions, ethics, welfare, health, social structures and, undoubtedly, cities and environment even beyond their physical appearance. Therefore, when the built environment is viewed as the highest and longest lasting achievement of human civilization, and the urban environment viewed as the summation of all tangible and intangible values connected with the progress of mankind, the terms “resilient” and “sustainable” sometimes come hand in hand, as if they would be interchangeable, and sometimes face discordant opposition (Garcia & Vale, 2017).