The Italian building heritage is aged and inadequate to the high-performance levels required nowadays in terms of energy efficiency and seismic response. Innovative techniques are generating a strong interest, especially in terms of multi-level approaches and solution optimizations. Among these, Nested Buildings, an integrated intervention approach which preserves the external existing structure and provides a new structural system inside, aim at improving both energy and structural performances. The research presented hereinafter focuses on the strengthening of unreinforced masonry (URM) buildings with cross-laminated timber (CLT) panels, thanks to their lightweight, high stiffness, and good hygrothermal characteristics. The improvement of the hygrothermal performance was investigated through a 2D-model analyzed in the dynamic regime, which showed a general decreasing in the overall thermal transmittance for the retrofitted configurations. Then, to evaluate the seismic behavior of the coupled system, a parametric linear static analysis was implemented for both in-plane and out-of-plane directions, considering various masonry types and connector spacings. Results showed the efficiency of the intervention to improve the in-plane response of walls, thus validating possible applications to existing URM buildings, where local overturning mechanisms are prevented by either sufficient construction details or specific solutions.

Green roofs and green and living walls are increasingly seen in cities, because they are an important strategy that addresses some key urban environmental issues and allows the achievement of different benefits. Among these, the most relevant ones are reduction of the “Urban Heat Island” effect, of rainfall contributions to the sewer system, of environmental impact and energy saving, and retention of harmful substance. The study aims to analyze different systems of greenery systems integrated (GSI), green roofs (GR), and green and living walls (GW-LW), as a possible retrofit technique of the envelope of heritage buildings and especially their applications in the context of historic cities in Italy, pointing out positive and negative aspects. Particularly, it pays attention to the green retrofitting of buildings and to the technical problems related to the installation of systems, since at the moment there are already several studies that show the environmental and microclimatic benefits of the integration of vegetation in architecture. This study tries to highlight the series of design procedures necessary both in the preliminary phase and then in the executive phase to relate the GSI to the existing building envelopes. The GR, from the results of the simulations conducted, demonstrate a greater simplicity in their construction, with improvements also from the point of view of the working loads on the existing structures, since the interventions are performed more easily than those on the facade. The study highlights the architectural needs that are not always considered such as the increase in the thickness of the roof and the related need to raise its edges, changing the perspective of the building. On the other hand, the GW and the LW show some complexity in their construction because they must deal with facades often rich in decorative elements and where openings affect the assemblage and connection works such as the tinsmiths of the intrados of the openings. It must be taken into consideration the necessity of having to drill masonry, often inhomogeneous, to connect fixings and the problems of stability this entails must be carefully analyzed.

Prefabricated residential construction forms a large portion of the European building stock and needs to be upgraded to current living standards and, if applicable, to current seismic resistance requirements. In fact, as indicated by the European Union in 2011, the refurbishment of the structures built during the second half of the twentieth century is priority for the entire construction sector. However, this process is affected primarily by the lack of knowledge of the material and construction aspects of prefabricated buildings, which makes the development of economic and efficient refurbishment interventions difficult. Based on this need, this paper focuses on the assessment of the seismic structural behavior of residential buildings built using the prefabrication procédé Camus, widely used in France and in many European countries, including Italy, during the 1960s. The analysis was carried out on a typological building placed in the city of Bologna, as this region concentrates an important number of prefabricated structures that had been recently affected by several earthquakes. Results show that due to the building layout, the analyzed structure has significantly higher lateral stiffness and better structural performance in the transverse direction than in the longitudinal direction. In fact, it was observed that the structural prefabricated walls located in the longitudinal direction will need to be strengthened in order to fulfill current requirements for shear strength and the combined effect of axial loads and bending moments.

Nested buildings today represent an efficient alternative to traditional recovery interventions in terms of cost-effectiveness, sustainability and compatibility with the existing building. The Italian territory has many disused industrial buildings on which it is necessary to operate with new recovery and re-market strategies. This article presents the results of the research, currently in progress, carried out by the ICEA department (University of Padua). The research concerns the recovery of industrial buildings in reinforced concrete from the 20th century. In these buildings the prefabrication allows a considerable optimization of the recovery interventions focused on modularity and prefabrication to fasten the construction times together with flexibility and reversibility. The analysis of the functional, structural and construction types made it possible to identify general intervention criteria which – as the identification of the average span dimensions – led to two design scenarios of wooden housing modules, following nested-building strategy. After a phase of study and critical analysis, criteria and guidelines for intervention were identified which – as the identification of the average span dimensions – led to two design scenarios of wooden housing modules, following nested-building strategy. The ex-Manifattura Tabacchi factory in Verona was chosen as a case study on which the results of the research were tested.

Nested buildings today represent an efficient alternative to traditional recovery interventions in terms of cost-effectiveness, sustainability and compatibility with the existing building. The Italian territory has many disused industrial buildings on which it is necessary to operate with new recovery and re-market strategies. This article presents the results of the research, currently in progress, carried out by the ICEA department (University of Padua). The research concerns the recovery of industrial buildings in reinforced concrete from the 20th century. In these buildings the prefabrication allows a considerable optimization of the recovery interventions focused on modularity and prefabrication to fasten the construction times together with flexibility and reversibility. The analysis of the functional, structural and construction types made it possible to identify general intervention criteria which – as the identification of the average span dimensions – led to two design scenarios of wooden housing modules, following nested-building strategy. After a phase of study and critical analysis, criteria and guidelines for intervention were identified which – as the identification of the average span dimensions – led to two design scenarios of wooden housing modules, following nested-building strategy. The ex-Manifattura Tabacchi factory in Verona was chosen as a case study on which the results of the research were tested.