Ongoing greenhouse gas emissions continue to accelerate global warming, with buildings contributing substantially to carbon dioxide emissions. Improving building envelopes is crucial for enhancing energy efficiency and resilience, especially as passive design strategies may become ineffective under extreme climatic conditions. Phase Change Material (PCM) glazing emerges as a promising solution to increase thermal inertia, reducing cooling energy consumption, and improving occupant comfort in office buildings. However, its impact on energy consumption under diverse climatic and operational scenarios remains underexplored. This paper presents a multivariate analysis of PCM glazing design variables -window-to-wall ratio (WWR), fa & ccedil;ade orientation, and PCM type- across ten climates in Europe and North America, considering two internal heat gain scenarios. Using a validated heat transfer model integrated into EnergyPlusTM, 4320 simulations were conducted to evaluate annual electricity consumption for heating, cooling, and lighting. Results show that PCM glazing can significantly reduce cooling energy use between 19 % and 45 % in arid/semiarid climates, when melting temperatures are optimally matched to diurnal temperature cycles (21-25 degrees C). Conversely, PCM glazing is less effective in tropical and cold climates due to limited phase change activation and high window U-values. Sensitivity analysis using Standard Regression Coefficients (SRC) reveals climate-dependent design priorities: PCM type dominates in arid/semiarid climates, WWR in tropical zones, and fa & ccedil;ade orientation in cold regions. The findings emphasize the need for climate-specific PCM glazing strategies and support the integration of adaptive glazing technologies into building codes and retrofit programs. This study offers actionable insights for architects, engineers, and policymakers to enhance building envelope performance and resilience in the context of climate change.

Heating and cooling account for a substantial proportion of building energy consumption, driving demand for structural materials with improved thermal performance. Lightweight aggregate concrete (LWAC) combines low density and thermal conductivity but exhibits reduced mechanical performance. Although aggregate porosity and volume fraction have been widely studied, the effects of pore-size distribution (PoSD) within lightweight aggregates (LWA)s and its relationship with the macroscopic behavior of LWAC remain insufficiently understood. Therefore, this paper presents LWACTM, a multiscale thermal–mechanical finite element framework developed in ANSYS Mechanical® to quantify the effects of PoSD on the thermal conductivity, Young’s modulus, and uniaxial compressive strength of LWAC. The framework explicitly represents the cement paste, the solid phase of the LWAs, and the air within LWA pores, thereby linking aggregate microstructure to concrete-scale performance. This framework considers that the cement paste is homogeneous and isotropic, pores are perfectly spherical and non-coalescent, heat transfer through LWA pores is mostly by conduction, and the LWAs and LWACs' thermal conductivity is in the dry state. Model predictions agreed closely with analytical bounds and experimental results, achieving R2 values of 0.95, 0.93, and 0.99 for thermal conductivity, Young’s modulus, and compressive strength, respectively. Parametric analyses showed that PoSD affects mechanical performance considerably more than thermal behavior within the investigated ranges. At an aggregate volume fraction of 70%, reducing the average pore size from 161 to 25 μm increased LWAC compressive strength by 30.7%, while thermal conductivity increased by only 1.1%. At the aggregate scale, the same pore-size reduction increased compressive strength by up to 80%. These findings identify PoSD as a key microstructural design variable for mitigating the trade-off between mechanical performance, thermal efficiency, and lightness. The proposed framework provides a practical basis for designing LWAC with enhanced structural performance while preserving its thermal-insulation and lightness benefits. The main limitations of this research are the two-stage modeling strategy due to the complexity of the aggregate–pore system and the exclusion of pores smaller than 10 μm.

New composites produced with recycled waste are needed to manufacture more sustainable construction materials. This paper aimed to analyze the hygrothermal and mechanical performance of plasterboard with a polymethylhydrosiloxane (PMHS) content, incorporating recycled PET microplastic waste and varying factors such as PMHS dose, homogenization time, and drying temperature after setting. A cube-centered experimental design matrix was performed. The crystal morphology, porosity, fluidity, water absorption, flexural strength, and thermal conductivity of plasterboards were measured. The results showed that incorporating recycled PET microplastics does not produce a significant difference in the absorption and flexural strength of plasterboards. However, the addition of recycled PET reduced the thermal conductivity of plasterboards by around 10%.

Although structural masonry walls are widely used in construction, achieving lower U-value is crucial to minimize energy losses and greenhouse gas emissions. The effect on the U-value of hollow clay masonry walls is evaluated by modifying the clay and mortar thermal conductivities, as well as the brick grid and thickness. Heat transfer through bricks and walls was modeled using a 3D-finite element method while model validation was based on experimental tests. Smaller rectangular cavities reduce the U-value to 0.761 W/m2K; increasing the brick thickness reduces the U-value to 0.563 W/m2K. Moreover, reducing the clay thermal conductivity showed negligible reductions in the wall U-value.

The cooling potential of vegetated roofs depends on the stomatal resistance (rs), leaf area index, and other factors. Sailor (2008) and Tabares-Velasco and Srebric (2012) are among the most cited heat and mass transfer vegetative roof models. They include different equations to estimate rs, which show large differences, and significantly overestimate rs under certain conditions. Therefore, their models offer particular opportunities for improvement to reflect the actual vegetation cooling potential. This is necessary to predict the impact of vegetative roofs more accurately on the building energy performance and the urban heat island effect. The rs of both vegetative roof heat and mass transfer models have been developed based on studies with species that are not commonly planted on vegetative roofs. It was found that both models overestimate the rs under certain conditions that could turn into the underestimation of the transpiration rates and the cooling potential. Consequently, this paper aims to develop a novel equation for rs based on field measurements in a semiarid climate. The species tested were Glandularia berterii (C3), Selliera radicans (C3), Phyla reptans (C3), Aptenia cordifolia (CAM), Sedum palmeri (CAM), and Sedum spurium (CAM). A New Linear Model (NLM) was formulated to estimate rs. The regressors of NLM are minimum stomatal resistance (rs,min), incident solar radiation (Rsh), leaf area index (LAI), substrate volumetric water content (VWC), and vapor pressure difference (VPD). The results show that rs,min and Rsh reflect 64 % of rs; the species with higher cooling potential were Selliera radicans, Sedum palmeri, and Sedum spurium due to higher LAI and lower/moderate rs,min; and, the NLM showed a better agreement with the measured rs, correcting points where Sailor (2008) and Tabares-Velasco and Srebric (2012) equations significantly overestimated rs. Finally, it was demonstrated that the developed NLM better represents the stomatal behavior and distinguishes the responses between C3 and CAM species.

Glazing filled with Phase Change Materials (PCMs) or PCM glazing arises as a strategy to improve the office buildings' energy performance by providing thermal inertia to glazed fa & ccedil;ades. PCM glazing can reduce office buildings' cooling energy consumption in warm climates. Literature shows a good understanding of PCM glazing thermophysical properties. However, nowadays, it is unfeasible to estimate the energy consumption of offices with PCM glazing based on annual energy simulations. Therefore, this paper aims to integrate a novel, developed, and validated PCM glazing heat transfer model for building energy performance applications into EnergyPlus. In order to do this, a numerical heat transfer model of a double-clear glazed filled with PCM based on literature is developed. This model is validated experimentally and integrated into EnergyPlus, a state-of-the-art building energy simulation tool. Annual simulations are carried out for an office room with different WWR, fa & ccedil;ade orientations, and PCMs in four climate conditions to show the model's capability to estimate the energy consumption and cooling peak load reductions. The results show that double-clear glazing filled with PCM can reduce the energy consumption of an office building up to 9.1 % and reduce the cooling peak loads up to 10.5 % compared to the same office building with a triple-clear glazing filled with argon. The best results were observed in warm climates with significant diurnal temperature variations.

Location determines not only the climatic condition but also the structural loads that the structure must withstand. Given the broad variety of climatic and seismic requirements of Chile, the design of lightweight timber buildings considering both energy and seismic design parameters and boundary conditions becomes a difficult task. The main objective of this research is to analyze and quantify the effect of climates, seismic loads, lateral anchorage, and story number on the optimal energy design solutions, including the seismic behavior in a light-frame timber building. Furthermore, the optimal design was parametrically analyzed considering five Chilean cities that consider different climates, seismic zone, number of stories, and lateral anchorage systems to prevent rocking (overturning) due to lateral seismic forces. The optimal wall insulation thickness, stud spacing, and thermal mass exhibited significant variations depending on the buildings' number of stories, lateral anchorage system, climate, and seismic zone. Therefore, the results of this investigation reinforce the necessity of integrating energy and seismic designs for light-frame timber buildings. The optimal designs obtained in this investigation showed considerable variations depending on the combination of climatic and seismic loads as well as the number of stories and anchoring systems. The article's main contributions are the evidence of the structural and energy design interconnection of light-frame timber buildings and how design variables, such as stud spacing, floor concrete thickness layer, and wall insulation thickness, are related and change according to the different climates, seismic loads, lateral anchorage, and story number.

HighlightsCrystal morphology and porosity of plasterboards are affected by polymethylhydrosiloxane dosage, agitation time, and drying temperature.Polymethylhydrosiloxane affects moisture resistance, mechanical strength, and thermal insulation of plasterboards.Water absorption and thermal conductivity decreased with addition of polymethylhydrosiloxane.Plaster board are more porosity and dense with polymethylhydrosiloxane.

Offsite construction methods have shown many advantages over traditional construction techniques, especially related to efficiency and productivity during the construction phase. Nevertheless, offsite construction generally involves oversizing the internal structure of the modules due to the internal stresses produced during transport and lifting operations, producing an increase in material usage, direct cost, and carbon footprint. In developing countries, the direct cost of social housing is the most important factor determining the feasibility of construction. For this reason, oversizing the internal structure of the modules can play an important role in the adoption of a modern construction technique such as offsite construction systems. In order to solve this issue, a temporary reusable stiffener structure is proposed to allow an economical offsite construction system using a lightweight steel framing structure used in traditional methods. The reusable structure was designed using a finite element method, and the direct cost and carbon footprint of the structure were evaluated. The results show that the proposed construction strategy allows for a low cost and reduced environmental impact due to a lower usage of materials in the modules and the possibility of a circular economy approach to the reusable structure.

Plasterboard is an important building material in the construction industry because it allows for quick installation of walls, partitions, and ceilings. Although a common material, knowledge about its performance related to modern polymers and fabrication conditions is still lacking. The present work analyzes how some manufacturing factors applied during the plaster board fabrication impact on some plasterboard properties, including water absorption, flexural strength, and thermal conductivity. The manufacturing variables evaluated are the dose (D) of polymethylhydrosiloxane (PMHS), the agitation time of the mixture (H), and the drying temperature of the plaster boards after setting (T). The results suggest that factors D, H, and T induce changes in the porosity and the morphological structure of the calcium sulfate dihydrate crystals formed. Performance is evaluated at two levels of each factor following a statistical method of factorial experimental design centered on a cube. Morphological changes in the crystals of the resulting boards were evaluated with scanning electron microscopy (SEM) and the IMAGEJ image analysis program. Porosity changes were evaluated with X-ray microcomputed tomography (XMT) and 3D image analysis tools. The length-to-width ratio of the crystals decreases as it goes from low PMHS dosage to high dosage, favoring a better compaction of the plasterboard under the right stirring time and drying temperature. In contrast, the porosity generated by the incorporation of PMHS increases when going from low-level to high-level conditions and affects the maximum size of the pores being generated, with a maximum value achieved at 0.6% dosage, 40 s, and 140 °C conditions. The presence of an optimal PMHS dosage value that is approximately 0.6–1.0% is evidenced. In fact, when comparing trails without and with PMHS addition, a 10% decrease in thermal conductivity is achieved at high H (60 s) and high T (150 °C) level conditions. Water absorption decreases by more than 90% when PMHS is added, mainly due to the hydrophobic action of the PMHS. Minimum water absorption levels can be obtained at high drying temperatures. Finally, the resistance to flexion is not affected by the addition of PMHS because apparently there are two opposing forces acting: on one hand is the decrease in the length–width ratio giving more compactness, and on the other hand is the generation of pores. The maximum resistance to flexion was found around a dosage of 0.6% PMHS. In conclusion, the results suggest that the addition of PMHS, the correct agitation time of the mixture, and the drying temperature reduce the water absorption and the thermal conductivity of the gypsum boards, with no significant changes in the flexural resistance.

Recently, living walls and vegetative roofs have emerged as envelope technologies that can save energy owing to the cooling effects of the building envelope. However, simulation models are required as part of the design support tools available for sizing greenery systems according to architectural constraints and climate. In this study, a green roof heat and mass transfer (GRHMT) model was adapted to develop a novel pot-based living walls heat and mass transfer (LWHMT) model to assess the cooling potential of living walls. The LWHMT model is validated using climate data for Santiago (Chile), which demonstrated a close agreement between the experimental data and the simulated foliage and substrate temperatures and substrate volumetric water content. Along with a previously established GRHMT model, the proposed LWHMT model was coupled to EnergyPlus (R) through the MLE+(R) toolbox to simulate the heat transfer between a building and several vegetative surfaces simultaneously. Finally, a prototype retail building was simulated, using climatic conditions for Santiago, to evaluate the impact of wall and roof insulation on the performance of the greenery system, with additional simulations performed for three cities in the USA (Atlanta, GA; Tucson, AZ; Tampa, FL) using different greenery system configurations. The living walls show cooling load reductions of 19.7-24.9%, while the green roofs show much lower reductions of 9.6- 15.1%. Moreover, the highest cooling load reductions were obtained by combining green roofs and living walls, achieving a maximum reduction of 36.8% compared with the base case building. In the future, the LWHMT model should be extended to continuous growing media such as pocket felts. In addition, GRHMT and LWHMT models should be integrated into building energy modelling software to develop the full potential of a parametric tool for greenery systems performance simulation. (c) 2022 Elsevier B.V. All rights reserved.

The building construction has a significant impact on sustainability worldwide. However, industrialised building systems (IBS) might reduce these impacts compared to traditional building systems (TBS). Previous literature reviews have analysed IBS's sustainability, based primarily on environmental aspects and through qualitative indicators, disregarding a detailed quantitative comparison between both technologies and nor considering economic and social sustainability indicators. To fill this gap, this paper aims to evaluate vis-à-vis IBS's sustainability in relation to TBS, based on the quantitative and qualitative indicators studied in the literature. Thus, an exhaustive bibliographic review of IBS and TBS case studies was conducted. In total, 67 scientific papers were selected (papers, book chapters and reports), containing 86 case studies. Major findings indicated that IBS are more sustainable in almost all studied values – except construction costs. Nevertheless, this advantage depends on material design, prefabrication levels, transportation, work management and each author's methodological approaches. These factors are discussed to explain the reasons for IBS′ sustainability. Furthermore, main conclusions indicate that sustainability assessments have been unbalanced in literature, with few analyses of economic and social performance, and some indicators have been poorly studied (e.g., water and acidification potential), so their results are not yet representative. Similarly, reusability, prefabrication levels and the social indicators of IBS were insufficiently analysed in the reviewed case studies. Finally, the current review highlights IBS sustainability indicators that have been less studied in order to motivate new investigations in the broader field, exposing the IBS sustainability outlook and other research gaps.

The structural and energy performance of the light-frame buildings is intrinsically linked, but the design process of both domains is not. Light-frame timber buildings are subjected to overheating due to the lack of thermal mass. A solution to eliminate or mitigate overheating is adding thermal mass, but the main drawback is increasing the seismic forces the building needs to withstand. Furthermore, the length of exterior shearwalls, fenestration openings, and studs spacing affect both the energy and structural performances. This paper aims to analyze and integrate energy and seismic-structural design variables for a light-frame residential timber building with different lateral seismic connectors and building stories. An Energy and Structural Timber Building Optimization (ESTIBO) methodology is proposed to integrate energy and seismic-structural design variables by optimizing the building energy performance. ESTIBO is based on GenOpt optimization software using a hybrid multidimensional optimization algorithm, while the energy simulations are performed on EnergyPlus using the Rhino's Grasshopper plugin. A structural model is implemented in Matlab under a modal response analysis of the building structure. The main results show that integrating critical design variables achieves different optimal values considering feasible structural solutions with reduced heating and cooling loads. It was found the four main variables that primarily reflect the link between energy and seismic-structural performances are stud spacing, wall insulation thickness, wall insulation type (high or low specific heat capacity), and floor concrete layer thickness. This paper contributes to improving the understanding of light-frame timber buildings' performance regarding the interaction of energy and structural-seismic design variables. Moreover, ESTIBO demonstrated to be able to provide optimal energy and seismic-structural solutions. Thus, it can support the early design stage of light-frame timber buildings.

There is extensive literature showing the effect of solar shading devices on energy savings, preventing overheating and achieving occupants' visual comfort in highly glazed office spaces. Nevertheless, solar protection devices can also significantly diminish the visual contact with the outside. This work evaluates the view to the outside through exterior solar shading fabrics and provides new data for development of a revised View Clarity Index. 50 subjects evaluated their view to the outside through nine fabrics of different colors and openness factors (OF) mounted on windows of identical test cells. In parallel, interior and exterior vertical and horizontal illuminances were monitored along with fabric luminance during each experiment. It was observed that the view to the outside was highly influenced by the fabric OF and color. The higher the OF and the darker the fabric, the clearer the view to the outside. However, their combined effect is quite complex. Interestingly, view clarity through the dark-colored fabric with OF=3% was estimated better than that of the light-colored fabrics with OF=10%. Based on the new data, a revised formula for the View Clarity Index (VCI) is proposed for predicting view clarity through fabrics, based on the normal-normal and normal-diffuse light transmittance factors of the material. Finally, the new findings show that the current performance classification scheme of the European standard EN 14501 needs further refinement. New classes are proposed as valuable information towards accurate assessment of outside view through fabrics in future revisions of the standard.

Office buildings are usually characterized by low thermal inertia, which could cause underperformance in terms of energy consumption. Moreover, the use of large, glazed façades in office buildings can cause thermal and visual discomfort due to high solar heat gains and excessive daylight transmitted into the office space. Phase Change Materials (PCMs) integrated into glazing have arisen as an innovative strategy to increase thermal inertia and improve office buildings’ energy performance and indoor comfort at a low cost. This paper aims to analyze the impact of PCM glazing on buildings’ energy performance and occupants’ thermal and visual comfort. The analysis is performed through a one-year real-scale experiment in two offices in Santiago, Chile, with an east-oriented façade and a window-to-wall ratio (WWR) of 56%. The results are analyzed on two timescales: seasonally and daily. Representative days in each season were selected to carry out the analysis. Regarding the energy consumption of the HVAC system, PCM glazing reduces energy consumption during summer and mid-seasons and significantly reduces the peak loads in summer. A meaningful improvement in thermal comfort is achieved due to the control of the mean radiant temperature for the whole year. Considering visual comfort, there is an improvement in the luminance distribution in winter and mid-season cold conditions.

Urban air quality has been a long-standing problem in most cities worldwide. Many strategies have been proposed to solve it, including green infrastructures such as green roofs (GRs) and green walls (GWs) that provide multiple environmental benefits. Many studies have focused on GRs and GWs strategies to mitigate urban air pollution. However, to the best of authors' knowledge, these studies have not dealt with different urban morphologies, specifically the impact of building heights and coverage ratios of GRs and GWs on mitigating air pollution. Therefore, the potential of GRs and GWs to alleviate air pollution has not been fully exploited. This paper aims to investigate different GRs and GWs layouts and evaluate their efficacy for capturing particulate matter (PM2.5) in an urban neighborhood of Santiago, Chile. We use ENVI-met model to simulate a metropolitan area with buildings, vegetation, paved surfaces, and traffic emissions to estimate air pollution abatement for varying building heights and coverage ratios of GRs and GWs. We simulate these layouts and coverage for a downtown area of Santiago, and results were compared with the base case scenario. Results showed that the air quality improvement by GRs and GWs depends on building height, surrounding urban infrastructure, vegetation cover and proximity to the pollutant source. Specifically, results showed that 50%-75% of GRs coverage on lowrise buildings could improve air quality at the pedestrian/commuter level. However, just a 25% coverage of GWs yields the highest PM2.5 capture. We conclude that to decrease PM2.5 concentrations, priority should be given to instal GRs in buildings lower than 10 m in height. For GWs, the PM2.5 abatement is favorable in all cases. ENVImet results also show that the combined use of GRs and GWs could reduce PM2.5 up to 7.3% in Santiago compared to the base case scenario.

Exposure to ambient PM2.5 poses serious threats to human health. In such cases, the presence of green roofs (GRs) and green walls (GWs) has several environmental benefits, including the capture of pollutants. Choosing appropriate designs of GWs and GRs to improve urban air quality is challenging because their performances depend on their constituent species and environmental characteristics of the particular locality. Capture of PM2.5 by different plant species of GRs and GWs has been measured only on monocultures. The impact of planting different species together (polycultures) on capturing PM2.5 remains unexplored. This paper aims to evaluate the impact of biodiverse GRs and GWs on PM2.5 capture. Seven species were analyzed as polycultures: Sedum album, Lampranthus spectabillis, Sedum spurium P, Lavandula angustifolia, Erigeron karvinskianus, Aptenia cordifolia, and Sedum palmeri. PM2.5 capture was measured by two methods: gravimetric determination and decay curve. Gravimetric results suggest that higher the biodiversity of plants in GRs and GWs, higher the PM2.5 capture, particularly for species with relatively low capture when used as monocultures. The ability to capture PM2.5 is dependent on the plant species, relative position of plants within the polyculture, and horizontal (GRs) or vertical (GWs) layout. Decay method results suggest that polycultures could be more effective in long-term reduction of high PM2.5 concentrations.

Phase Change Materials (PCMs) are materials with high latent heat. When integrated into the glazing, they arise as an innovative strategy to improve thermal performance and provide thermal inertia in office buildings with a lack of opaque. Climates with high solar radiation and great temperature variation between day and night are especially interesting because PCM glazing can vastly improve these buildings’ energy performance. Then, this paper aims to analyze the energy performance of an office room with PCM glazing compared to a reference room with double-clear glazing, in a semi-arid climate. A real-scale experiment was carried out for a year in two office rooms located in Santiago, Chile. The analyses include energy consumption of the HVAC system to keep the interior temperature of the room in the comfort range and the solar radiation transmitted through the windows. Results are presented for three representative weeks of summer, mid-season and winter. An important reduction of the solar radiation transmitted was achieved in the PCM glazing in respect to the double-clear glazing when the phase change occurs, and a decrease of the energy consumption of cooling and heating mainly for sunny and variable days was found.