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As of 2021 all new buildings within the European Union will be nearly Zero Energy Buildings (NZEB). Different plans are being promoted by member states to reach this goal, to increase the number of NZEBs and to facilitate the retrofit of existing constructions. Within this frame, several analyses of cost benefits have been developed to evaluate the economic effectiveness of retrofit interventions. The economic analysis can be extended to the energy and environmental fields introducing various indicators, such as energy and environmental payback times, to describe the effectiveness of the retrofit intervention from a more extensive point of view. In this paper, we considered a school building located in Turin (Northern Italy) with the scope of evaluating the energy and carbon payback times of different retrofit scenarios that could be implemented for the existing building. An optimal cost retrofit and two NZEB retrofits were considered, varying envelope insulation, heat generation and lighting systems, shading and control devices. First, we simulated the building's energy consumption and calibrated the results with data from actual energy bills. The calibrated model was used for evaluation of the building's energy demand after the proposed retrofit interventions. We then applied the Life-Cycle-Analysis (LCA) for the calculation of environmental payback times. The results showed that the NZEB retrofit produces energy and environmental payback times that are shorter than the life cycle of the building. In the foreseeable future, solutions such as these could prove effective in addressing issues that arise from global warming and energy supply.

The current environmental and energetic crisis and the resulting regulations led to a new interest in using sustainable materials for building applications. Wood can be a material with high sustainable rates because it is recyclable, reusable and naturally renewable. Moreover, its excellent strength-to-weight ratios, thermal insulating and acoustical properties make it useful for different kinds of applications in buildings, ranging from structural beams and frames, insulating envelopes, windows, door frames, to wall and flooring materials and furniture. Although wood is commonly classified as a sustainable material, its real sustainability depends on different issues: appropriate forest management, manufacturing methods and site assembly, distance required for transportation and use of glues. Wood has also good seismic performances due to its lightweight and even if timber elements are not able to have a ductile behavior, using steel connection allows to build dissipative structure, as well platform frame and X-LAM panels systems. Insulation properties are related to low thermal conductivity values. Furthermore, wooden elements can be used to minimize sound transmission and they can be employed as sustainable materials as several Life Cycle Assessment studies demonstrate. This review paper aims to analyze the structural, thermal, acoustical and environmental properties of wooden materials for building applications; other properties such as fire resistance and durability were also taken into account. The work is completed by several tables and graphs with wood properties and by an updated and thorough reference list.

Passive systems are acknowledged to highly optimize the thermal and energy performance of buildings. A detailed literature review shows that solar shading technologies play a key role in improving indoor thermal and lighting behavior according to outdoor environmental condition. Moreover, the possibility to control their dynamic operations by means of automatic systems is showing promising findings. In this view, the present paper aims at analyzing the thermal and lighting performance of a full scale test room with varying the layout of an external venetian blind system. In particular, the test-room was continuously monitored in two different periods with the purpose of evaluating the effects of several shading system configurations compared to an automatic one, controlled by outdoor selected parameters (air temperature and illuminance). The experimental apparatus consists of a full scale prototype building designed considering Italian typical residential buildings in terms of envelope materials and geometry (transparent and opaque envelope area). The shading layout was periodically modified with the final objective of quantifying the effect of such modifications in terms of indoor thermal and lighting performance. The results show that the different configurations of the venetian blind hugely affect indoor thermal and lighting performance. In particular, the dynamic behavior of the automated venetian blind is able to produce the highest benefits.

The paper presents a comparison between two different rating systems to evaluate buildings sustainability: LEED (USA) and ITACA (Italy), thanks to the application of both methods to two residential buildings located in Italy. The LEED green building rating system encourages an integrated design approach, with a points scheme that allots credits for building design features deemed to improve sustainability, which includes reductions in energy use, improvements in indoor environment quality, protection of the construction site, reduction in water consumption and use of sustainable materials. ITACA procedure, the environmental quality rating system adopted in Italy, consists of the compilation of a group of worksheets, one for each different performance indicator, at the aim of describing the building environmental quality, including the maintenance of indoor comfort during the entire life cycle. The chosen buildings are located in central Italy; they are both energy efficient and designed according to the principles of bioclimatic architecture, even if they are characterized by different features. Five common areas (site, water, energy, materials, indoor environmental quality) were identified in order to compare the two methods and to normalize their score; this original approach can be transferred also to the comparison of other building environmental assessment tools. The comparison allows to prove the main features of both schemes. Even though the two procedures give different importance to the various areas, the analysis show a proportionality between the respective normalized final score for the two examined buildings.