Achieving sustainable urban environments is a challenging goal—especially in existing cities with high percentages of old and obsolete buildings. This work analyzes the contribution of roof refurbishment to sustainability, considering that most roofs are currently underused. Many potential benefits of refurbishment can be achieved, such as the improvement of the energy performance of the buildings and the use of a wasted space for increasing green areas or for social purposes. In order to estimate the degree of the improvement, a vulnerable area in Castellón (east Spain) was selected as a case study. A thorough analysis of the residential building stock was undertaken. Using georeferenced information from the Cadastral Office we classified them according to typology, year of construction and roof type. Some refurbishment solutions were proposed and their applicability to the actual buildings was analyzed under different criteria. The theoretical benefits obtained in the neighborhood such as energy and carbon emissions savings were evaluated, together with the increase of green areas. Moreover, other social uses were suggested for neglected urban spaces in the area. Finally, a more accurate analysis was performed combining different solutions in a specific building, according to its particular characteristics.

The aging of the building stock in most cities highlights the relevance of refurbishment to achieve sustainability. Current refurbishment practices are often short-sighted and do not encompass holistic strategies beyond energy saving. This research study aims to analyze the factors involved in roof refurbishment versus current decision-making determinants. The objective is to identify the barriers that hinder their implementation and to find arguments to support roof renovations. A multicriteria analysis, which considered environmental, economic and performance factors, was employed to select optimal roof refurbishment solutions. This study evaluated five solutions. With interviews held with construction professionals and a survey of experts and homeowners, the preferences and criteria for making decisions about roof refurbishments were analyzed. Simulation tools were then used to estimate the energy savings, payback periods and environmental impact for a representative building in the study area. The results were extrapolated to a neighborhood level. The results highlight the importance of considering factors, such as weight, cost and user preferences when selecting suitable refurbishment solutions. The findings not only estimate the potential energy savings and carbon emission reductions in the area but also underscore the relevance of roof refurbishments for prolonging a building’s life span to contribute to sustainability.

Depopulation consists of the decrease in the number of inhabitants of a region, and in Europe, isconcentrated in rural areas. The state-of-the-art reveals that there has been extensive research across multipledisciplines, but that studies on housing are scarce. However, having a home, although not sufficient, is necessary to inhabit a place. This study analyses housing in depopulated rural communities. A municipality in Spain andanother in Italy were selected, applying the comparative method. A top-down approach was used, creatingsystematic data collection sheets. This was complemented by a bottom-up perspective, which is particularlyrelevant in these areas, where macro data can obscure local data. Through visual inspection of the dwellings andsemi-structured interviews, detailed and up-to date data and GIS maps are provided, offering new synthetic andvisual information. The transnational analysis reveals similarities in the poor state of conservation of underutilised housing, which requires large investments, and little real estate activity. There are regional differences that affect the type of housing and demand. Finally, the importance of public administrations treating rural areas asa complement to urban areas in order to maintain territorial balance and equity is highlighted.