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Modern architectural concept of “vertical forest” boosts the tendency of including permeable and green spaces in buildings and its surroundings. However, whilst green spaces generally make buildings and cities more ecofriendly, it is insufficiently known to which extent the surrounding environment and the vegetation may positively or negatively influence the pedestrian-level wind comfort quality of buildings amidst historical and well-settled urban layouts. This was the scope of the present study for which wind-tunnel (WT) testing and 3D RANS simulations were performed on two facing towers in Medellin (Colombia), in order to (i) investigate the wind field and the pedestrian-level wind comfort around the towers; (ii) to compare the performance of WT and 3D RANS for wind comfort analysis; (iii) to evaluate the impact of the environment surrounding the two towers and (iv) the mitigation effects of vegetation on wind comfort. WT tests were performed on a scaled model (1:250) without surrounding, for 12 wind directions and 3 sets of measurement positions. The same case study without (i.e. CFDs) and with (i.e. CFDd) surrounding environment was simulated by 3D RANS. Next, an implemented CFDd case including vegetation (i.e., CFDd-V) was simulated for three LAD values. Overall, the surrounding had a significant impact on wind comfort assessment. The CFDd case showed a better-quality class than WT and CFDs. The CFDs and WT case showed a satisfactory agreement and the similar comfort quality class. The vegetation provided a remarkable improvement of comfort quality class mainly for set 1 and 2.

The urban heat island (UHI) effect is among the most critical issues caused by human activities and high building density. UHI has severe impacts on the urban and natural environment as well as on human health and wellbeing. The research presented here aims at evaluating the effects of nature-based solutions (NBS) in improving the livability of a district in the city of Genoa, which is heavily cemented and a major example of the heat island phenomenon. This study focuses on the microclimatic benefits of urban heat island mitigation as well as on psychological and perceptual aspects. A preliminary analysis of the district through CFD simulations using Envi-met software allowed for selection of the most suitable areas for a system of punctual interventions in urban regeneration using nature-based solutions. For each area identified, we simulated the effects of different design scenarios on microclimate mitigation and thermal comfort improvement. In addition, to evaluate the perceptual benefits of the most well-performing design scenarios, we set up a web-based survey that was administered to a convenience sample of Genoa residents. In terms of aesthetic satisfaction and perception of improved conditions of physical and psychological well-being, the preferred design outcomes were those which emphasized a freer and more natural environment. This study shows that nature-based solutions can improve the overall conditions of dense urban areas, microclimate performance and psychological effects should be both considered in the design process in order to improve the wellbeing of urban citizens.

Urban greening provides a wide range of ecosystem services to address the main challenges of urban areas, e.g., carbon sequestration, evapotranspiration and shade, thermal insulation, and pollution control. This study evaluates the environmental sustainability of a vertical greening system (VGS) built in 2014 in Italy, for which extensive monitoring activities were implemented. The life-cycle assessment methodology was applied to quantify the water–energy–climate nexus of the VGS for 1 m2 of the building’s wall surface. Six different scenarios were modelled according to three different end-of-life scenarios and two different useful lifetime scenarios (10 and 25 years). The environmental impact of global-warming potential and generated energy consumption during the use phase in the VGS scenarios were reduced by 56% in relation to the baseline scenario (wall without VGS), and showed improved environmental performance throughout the complete life cycle. However, the water-scarcity index (WSI) of the VGS scenarios increased by 42%. This study confirms that the installation of VGSs offers a relevant environmental benefit in terms of greenhouse-gas emissions and energy consumption, however, increased water consumption in the use phase may limit the large-scale application of VGSs.

The last decades witnessed an unexpected spread of the concept of sustainability. This phenomenon has also involved the urban and architectural design field for its obvious and known environmental impact. This cultural process, undoubtedly positive, is leaving a trace in our time more than others. It is leading to a growing awareness of the environmental problem, to an ever-wider diffusion of new design approaches and new technologies and to a significant reduction in energy consumption and polluting emissions. However, this same cultural process has exponentially accelerated over the last decades, partly because of emergency circumstances, causing an extreme simplification of its content and a subsequent rise in false beliefs. An example is the belief that the direction towards environmental culture is going is unambiguous and commonly shared. The following essay is a reflection on this false belief and its possible consequences.

The building sector accounts for 40% of energy use and 25% of CO2 emissions, mainly due to inefficient building practices and energy consumption during the operational phase of buildings. Social housing accounts for a significant proportion of the European building stock and about 50% of the existing buildings are likely to require large-scale renovations in the coming years, meeting the current EPBD directive. This could represent an opportunity to renovate the affordable building stock, often characterized by premature disrepair, resulting in a bad perception from inhabitants and community. Significant European experiences have already shown the importance of an integrated approach finalized to the construction or renovation of social housing, leveraging on environmental sustainability, creating urban identity, adopting measures to face social disadvantage, offering at the same time quality housing standard. In this regard, it seems necessary to match technological advancements and knowledge in energy retrofitting with social needs and habits. The implementation of energy-efficiency improvements in social housing requests support and participation of the final energy consumer. The paper investigates how to deal with knowledge gaps in the relationship between retrofit technologies and users’ behaviour and possible strategic measures to increase awareness between tenants through two case studies.

Vertical greening systems and green roofs provide ecosystem services in the urban context. Despite the important benefits they provide, economic (initial and maintenance costs) and environmental issues may limit the widespread diffusion of these greening systems. Mosses can be a low-cost and low-maintenance alternative green envelope for large-scale application on existing urban and industrial buildings thanks to their low requirements in terms of growing substrates, low amount of water and nutrients needed, and high desiccation tolerance. The study assesses the’ growing ability of mosses on building materials and low-cost materials, by means of growing tests performed under controlled environmental conditions on horizontal and vertical surfaces. Moss growth depends mainly on the physical characteristics of the materials, although an acidic moss mixture improves species richness. Results show different surface coverage: capillary matting > cement plaster > lime plaster > terracotta brick > slate > quartzite. The water retention capacity and its homogeneous distribution on the growing surface are the limiting factors for moss growth.

In Europe, buildings are responsible for 40% of the energy consumption and 36% of the CO2 emissions. Space heating largely contributes to these energy and climate impacts. Passive solar heating systems, as sunspaces, can contribute to increase solar heat gains, reducing space heating energy demand and the related use of fossil fuels. Careful design and local climatic considerations are essential to optimize the performance of sunspaces. In this study experimental field monitoring, dynamic modelling and steady-state methods are applied to analyse the thermal behaviour of an attached sunspace in an Italian existing building, as well as its potential contribution to the building’s energy balance. Design modifications for improved thermal performance of the sunspace are investigated. The results show overall agreement between the dynamic modellings and experimental monitoring of the sunspace and indicate that the sunspace’s indoor air temperature and hence solar energy gains are significantly increased with the design modifications, in contrast to the existing configuration. Maximum temperatures between 44 and 48 °C were observed for the existing and a modified alternative of the analysed sunspace. The dynamic simulation model and design modifications presented in this study can serve as basis for assessment and optimal configurations of sunspaces in their design stage.

This paper comes from previous investigations carried out by the authors, in France and Italy, and from a cross border cooperation projects based on the joint collaboration between the University of Corsica Pascal Paoli and the University of Genoa. The authors focus on the enhancement of passive solar systems and thermal solar systems, with particular attention to their operation/efficiency and their architectural integration. The exchange between Italian and French experiences, especially between regions with similar climate, can enhance solar building strategies, in accordance with the new European energy standards as well as the Mediterranean climate, the traditional construction technologies and users’ needs.

Data shows that buildings play an important role in the field of energy efficiency and environmental sustainability. The exchange of information among different countries is a key element to promote a wider diffusion of practices for sustainable development in the fields of architecture and urban planning, contributing to the improvement of new skills and economic and production activities, while also reducing the environmental impact of construction on the territory. An international cooperation can lead an exchange of experiences and practices, which could play a fundamental role since countries can have similar problems to deal with, as it happens for the specific identity of the Mediterranean territory in coastal and rural areas. This paper analyses a case of international cooperation, the project SCORE, “Sustainable COnstruction in Rural and fragile areas for energy Efficiency”, financed under the European MED Programme with the purpose to promote sustainable energy policies in the construction sector on fragile coastal and rural Mediterranean areas.