A city and its historical and cultural heritage mutually influence each other. Since this heritage is a valuable resource for the city, the rich interaction between the two entities is extremely significant. In fact, it can even be regarded as an achievement, resulting in the revitalization of a wide range of urban historical areas and structures. This revitalization is reflected in the functional updating and adaptation of buildings as well as in transformations of even greater transcendence. Nevertheless, any changes in original function should be selectively taken on board by competent authorities and institutions, especially since this exercise in critical thinking necessarily implies the valorization of historical, typological, formal, constructional, and symbolic characteristics, which define these spaces as well as their relation with their surroundings. The scientific discipline in which such actions are performed demands that all agents involved respect and comply with different criteria; whose ultimate purpose is the preservation of this important historical and cultural heritage. For example, there are cases in the city of Granada (Spain) that vividly reflect these practices. In fact, they have become the focus of great interest because of the sweeping changes involved; which go beyond the mere preservation of the city's heritage. These historical buildings have now acquired very diverse functions, such as the following: (i) residential buildings, which can be one-family or multi-family dwellings, as fomented by urban planning strategies, (ii) buildings for institutional purposes and uses; (iii) buildings that have been adapted for a wide variety of cultural activities; (iv) buildings reconverted into small boutique hotels or hotels "with charm". This paper examines the most relevant factors that converge in this type of rehabilitation. It also studies the results of this revitalization process by examining specific examples, which directly and explicitly show the consequences derived form this change in building use, as analyzed in terms of social, urban, aesthetic, and technical parameters.