Search Results (27)

This study develops a comprehensive evaluation framework for urban street alfresco spaces by integrating the Analytic Hierarchy Process (AHP) and Entropy Weight Method. Daxue Road in Shanghai is selected as a representative case to analyze key factors influencing urban street alfresco spaces, which refer to commercially utilized outdoor extensions of building facades along streets, typically in the form of semi-open, publicly accessible areas used for dining, vending, seating, or temporary retail activities. These spaces are typically operated by adjacent businesses or regulated by local policies, and they integrate pedestrian circulation, commercial vibrancy, and spatial adaptability. They serve as critical urban interfaces that foster street-level vibrancy, social interaction, and public life. The evaluation system covers five dimensions: Cognizability, Accessibility, Participation, Emotional Design, and Spatial Diversity. The methodological innovation lies in integrating subjective weights derived from AHP with objective weights obtained through entropy calculations, which enhances the scientific rigor and neutrality of the evaluation. The results show that traffic safety (weight = 0.0644) and locational attributes of streets (weight = 0.0574) are the most influential factors affecting user perception. Compared to previous studies that often prioritize visual aesthetics or commercial density, this study underscores the significance of traffic-related factors, indicating a shift in user preferences in high-density urban environments. The findings provide practical guidance for urban design and policy to improve the quality, safety, and vitality of street-level public spaces in high-density cities. This research contributes to the theoretical foundation for sustainable and human-oriented street regeneration. Full article

Photosynthetically Active Radiation (PAR) is critical for sustaining plant growth in the ground and on building surfaces, but how to accurately predict PAR availability in a complex urban environment can be a challenge. Using an advanced ray-tracing software (Radiance 4.0) and local weather data, this study presents a dynamic analysis of the effects of layout, façade orientation and height on PAR availability in four high density residential areas in Shanghai city, China. A metric system was also adopted using three light level requirements of outdoor plants (low, medium, high light levels). Key findings included: (1) the urban layout with the highest ratio of building height to north–south facing adjacent building separation achieved the higher levels of PAR availability for low/medium light level plants and the lower levels of PAR availability for high-light plants for middle and low façades and the ground, while high façades in all layouts could see similar PAR availability for all plants. (2) The PAR availability for low/medium-light plants decreased with the increasing façade height, while the PAR availability for high-light plants showed the opposite trend. (3) The north façade and its ground had higher levels of PAR availability for low/medium-light plants and lower levels of PAR availability for high-light plants than other façades. (4) All layouts offered more opportunities to apply high-light and medium-light plants at façades and the ground. Full article

This study explores the challenges faced by traditional dwellings amid modernization and urbanization, with a particular focus on Huizhou dwellings, which struggle with issues such as inefficient space use and suboptimal spatial quality. This study employs UWB (ultra-wideband) indoor positioning technology to examine differences in residents’ production/living behaviors and their spatial usage preferences between two Huizhou traditional dwellings with distinct preservation statuses during both the summer and winter seasons. The study reveals the following findings: (1) The hall, courtyard, and kitchen spaces are the most frequently used living areas, followed by wing rooms and patio spaces. Differences in spatial organization patterns significantly influence residents’ preferences for alternating between various functional spaces. Residents tend to favor functional spaces centered around or adjacent to key circulation areas; (2) In summer, the patio space provides shade and ventilation, creating a cool and comfortable environment that supports a variety of living activities, resulting in high utilization rates. In winter, however, the patio space hinders heat retention for the inner facade, leading to lower temperatures and reduced usage; (3) The utilization rate of wing room spaces has significantly improved after simple renovations, whereas unrenovated wing rooms and side rooms exhibit relatively low utilization rates; (4) During fine weather in winter, the courtyard space maintains a relatively comfortable temperature, making it highly utilized. In contrast, the courtyard becomes excessively hot in summer, leading to significantly lower utilization rates compared with winter. By analyzing residents’ behavioral trajectories, the study explores the differences in living behaviors and their correlation with residential spaces across the different seasons and preservation states of traditional dwellings. These results offer important perspectives for the sustainable development of residential conservation and renewal efforts. Full article

This study addresses daylighting to enhance the quality of indoor atmospheres, considering building skins. In the hotel industry, lighting accounts for more than 10% of energy consumption. Many highly glazed façades create visual comfort problems, resulting in increased electric lighting consumption. Ninety-four restaurants were studied in Spain; almost all cases have a window with outside views, and more than half of the cases have tables adjacent to the outside views. However, it is difficult to balance daylight use, a shading system, and the outside view. A virtual restaurant prototype is built by Rhinoceros to simulate the daylight glare index by Evalglare and daylight autonomy of a highly glazed façade with three different shading systems by Radiance through a screen and an overhang with and without a complex fenestration system. The results show that the screen system reduces the daylight glare index value to imperceptible glare (15%), while the daylight glare index for the overhang with and without a complex fenestration system increases to acceptable glare (21%). However, the daylight autonomy for the screen system is almost half (52%) the daylight autonomy for the overhang systems (95%). Although the daylight glare index for the overhang with a complex fenestration system is slightly higher, the illuminance level and its distribution performance are better without obstructing the outdoor view. Full article

This study adapted the mean age of air, a time scale widely utilized in evaluating indoor ventilation, to assess the impact of building layouts on urban ventilation capacity. To distinguish it from its applications in enclosed indoor environments, the adapted index was termed the effective mean age of air (${\overline{\tau }}_E$). Based on an experimentally validated method, computational fluid dynamic (CFD) simulations were performed for parametric studies on four generic parameters that describe urban morphologies, including building height, building density, and variations in the heights or frontal areas of adjacent buildings. At the breathing level (z = 1.7 m), the results indicated three distinct distribution patterns of insufficiently ventilated areas: within recirculation zones behind buildings, in the downstream sections of the main road, or within recirculation zones near lateral facades. The spatial heterogeneity of ventilation capacity was emphasized through the statistical distributions of ${\overline{\tau }}_E$. In most cases, convective transport dominates the purging process for the whole canopy zone, while turbulent transport prevails for the pedestrian zone. Additionally, comparisons with a reference case simulating an open area highlighted the dual effects of buildings on urban ventilation, notably through the enhanced dilution promoted by the helical flows between buildings. This study also serves as a preliminary CFD practice utilizing ${\overline{\tau }}_E$ with the homogenous emission method, and demonstrates its capability for assessing urban ventilation potential in urban planning. Full article

Buildings are significant components of digital cities, and their precise extraction is essential for the three-dimensional modeling of cities. However, it is difficult to accurately extract building features effectively in complex scenes, especially where trees and buildings are tightly adhered. This paper proposes a highly accurate building point cloud extraction method based solely on the geometric information of points in two stages. The coarsely extracted building point cloud in the first stage is iteratively refined with the help of mask polygons and the region growing algorithm in the second stage. To enhance accuracy, this paper combines the Alpha Shape algorithm with the neighborhood expansion method to generate mask polygons, which help fill in missing boundary points caused by the region growing algorithm. In addition, this paper performs mask extraction on the original points rather than non-ground points to solve the problem of incorrect identification of facade points near the ground using the cloth simulation filtering algorithm. The proposed method has shown excellent extraction accuracy on the Urban-LiDAR and Vaihingen datasets. Specifically, the proposed method outperforms the PointNet network by 20.73% in precision for roof extraction of the Vaihingen dataset and achieves comparable performance with the state-of-the-art HDL-JME-GGO network. Additionally, the proposed method demonstrated high accuracy in extracting building points, even in scenes where buildings were closely adjacent to trees. Full article

Unreinforced masonry (URM) buildings in historic urban areas of European countries are generally clustered in an aggregate configuration and are often characterized by façade walls mutually interconnected with adjacent ones. As a result, the seismic performance of buildings in an aggregate configuration can be affected by the mutual interaction between the adjacent units. This interaction, often called the aggregate effect, could significantly influence the level of the seismic vulnerability of URM buildings in aggregate configuration toward in-plane and out-of-plane mechanisms, the latter being the object of the present paper. Traditional methods for assessing the seismic vulnerability of URM buildings neglect the interactions between adjacent buildings, potentially underestimating the actual vulnerability. This study aims to derive fragility curves specific for UMR buildings in aggregate configuration and proposes an innovative methodology that introduces the aggregate effect into an analytical approach, previously developed by the authors for isolated URM buildings. The aggregate effect is modeled by accounting for the friction forces arising among adjacent facades during the development of out-of-plane overturning mechanisms by considering different scenarios, based on how façade walls interact with neighboring structures (e.g., whether they are connected to transverse and/or lateral coplanar ones). The proposed approach is applied to a real case study of an Italian historical center. The obtained results demonstrate that the aggregate effect significantly influences the fragility curves of URM buildings arranged in aggregate configurations. This highlights the importance of considering this effect and the usefulness of the proposed approach for large-scale assessments of seismic vulnerability in historic urban areas, contributing to sustainable disaster risk prevention. Full article

Cities face the consequences of climate change, specifically the urban heat island (UHI) effect, which detrimentally affects human health. In this regard, deploying PV modules in urban locales prompts inquiry into the impact of energy-active building components on the adjacent thermal microclimate and human thermal comfort. A twofold simulation-based methodology addresses this subject: First, the implications of façade-integrated photovoltaics on the urban thermal microclimate are investigated using a case study in Munich, Germany. Secondly, a parameter study allows us to gain further insights into the relevance of several parameters on the microthermal impact. The simulation results show a daytime heating effect of photovoltaics on the mean radiant temperature of up to +5.47 K in summer and +6.72 K in winter. The increased mean radiant temperature leads to an elevation of the Universal Thermal Climate Index of up to +1.46 K in summer and +2.21 K in winter. During night-time, no increase in both metrics is identified—hence, nocturnal recovery as a key element for human health is not affected. Despite extended human exposure to thermal heat stress in summer, PV façades improve the annual outdoor thermal comfort autonomy by 0.91% due to lower cold stress in winter. The higher PV efficiencies and lower albedo of the reference building surface lower the heating effect. However, with the current efficiencies, PV façades consistently lead to heating of the surrounding thermal microclimate in summer and lower the outdoor thermal comfort. Full article

Taiwan is the fourth most urbanized country in Asia, where the urban spatial structure of high-rise and density hinders urban ventilation. Studies have proven that opening buildings reduce the area of windward surfaces, which can effectively mitigate the urban heat island effect and disperse pollutant accumulation. Until now, most researchers have discussed the differences in heights and sizes of openings in the opening buildings, but few discussed the influence of opening patterns on urban ventilation. Thus, we set the building unit to 30 × 30 m with 160-m height with the opening height as tall as 0.45 times the building height and a 9% opening rate, distributed in 6 × 6 ideal city configuration Four cases (case A: no opening, case B: middle square, case C: right square, and case D: middle rectangular) with different arrays of opening buildings were compared with ANSYS Fluent v18 to simulate the wind environment and NO₂ pollutants. The results showed that the opening building improved the permeability of street ventilation and air circulation, which greatly increased the wind speed at a height of 72 m. The distribution of pollutants was affected by the distance from the pollution source and the width of the street. Pollutants were gradually dispersed as the height increased. Case D of a long-narrow rectangular opening (adjacent to the pedestrian floor) and the venture effects formed eddy currents above and below the opening, which effectively improved the ventilation in the street canyon. Therefore, it had the best wind speed on the pedestrian level among the cases. The wind speed of the 72 m-high floor was much higher than that of case A, and the vortex generated by the airflow flowing through the opening in the street canyon increased the diffusion effect of pollutants. Overall, the opening building with a rectangular opening was the optimum solution in terms of wind speed improvement and pollutant removal. In addition to the opening design in the building facade, it is recommended to provide sufficient open space to improve air circulation in the building block and disperse pollutants. Full article

In the unfortunate event of a fire, within the context of the evolution of façade fires, with a specific focus on the utilization of polystyrene thermal insulation (external thermal insulation composite system façades—ETICS façades), this study delves into the investigation of fires ignited by containers containing plastic bottles. Through an examination of the fluctuating temperatures within the affected room and its adjacent areas, as well as an assessment of the fire’s impact on polystyrene thermal insulation, this paper underscores the significance of incorporating non-combustible barriers into the building’s thermal insulation system. The tests conducted revealed that the temperature inside the room reached a maximum of 1100 °C, subsequently decreasing to 800 °C at a height of 2.5 m and approximately 400 °C at a height of 5 m. For this research, two 1100-L containers of household waste were employed, each weighing 45.5 kg and possessing a gross calorific value of 46.97 MJ/kg, with 10.7 kg of PET bottles inside, characterized by a higher calorific value of 23.90 MJ/kg as the source of the fire. Heat release rate highest values were obtained between 11 and 17 min, with a maximum value of 4919 kW. Thus, even in the absence of specific legislation, this study emphasizes the imperative need to establish safety distances for the storage of household waste away from the building’s façade to mitigate the risk of fire propagation, particularly in relation to materials such as polystyrene thermal insulation. Furthermore, in certain situations, extensive fire experiments on a grand scale, like the one undertaken in this research, hold a crucial position in confirming numerical findings for global researchers. This process assures the reliability and real-world usefulness of fire safety studies through the experimental outcomes presented in this investigation. Full article

This research aims to implement green walls as thermal insulators on the east and west facades of the adjacent areas of the School of Biological Sciences at Ricardo Palma University. The growth of urban cities causes an increase in CO₂ emissions and the loss of agricultural land. The methodology applied involves evaluating the thermal behavior, analyzing the local climate, and assessing plant species for implementation. As a result, the successful implementation of green walls on the east and west facades was achieved, which has proven to effectively reduce wall heating, decrease the temperature rise in nearby spaces, and minimize reliance on artificial ventilation systems. This has led to energy and cost savings, decreased CO₂ emissions, and increased oxygen production. By implementing green walls on the east facade, there has been an increase of 60.73% in comfort hours, while on the west facade, there has been an increase of 64.28% in comfort hours. In addition, a total of 977.50 kg of CO₂ has been absorbed, resulting in 722.50 kg of purified air. In conclusion, green walls have proven to be a viable solution to the problems faced in urban cities, helping to mitigate the internal temperature of indoor spaces. Full article

Artificial intelligence and machine learning, in particular, have made rapid advances in image processing. However, their incorporation into architectural design is still in its early stages compared to other disciplines. Therefore, this paper addresses the development of an integrated bottom–up digital design approach and describes a research framework for incorporating the deep convolutional generative adversarial network (GAN) for early stage design exploration and the generation of intricate and complex alternative facade designs for urban interiors. In this paper, a novel facade design is proposed using the architectural style, size, scale, and openings of two adjacent buildings as references to create a new building design in the same neighborhood for urban infill. This newly created building contains the outline, style and shape of the two main buildings. A 2D building design is generated as an image, where (1) neighboring buildings are imported as a reference using the cell phone and (2) iFACADE decodes their spatial neighborhood. It is illustrated that iFACADE will be useful for designers in the early design phase to create new facades in relation to existing buildings in a short time, saving time and energy. Moreover, building owners can use iFACADE to show their preferred architectural facade to their architects by mixing two building styles and creating a new building. Therefore, it is presented that iFACADE can become a communication platform in the early design phases between architects and builders. The initial results define a heuristic function for generating abstract facade elements and sufficiently illustrate the desired functionality of the prototype we developed. Full article

During rescue operations, one of the important parameters determining the effectiveness of the implementation of tactical mechanical ventilation is the selection of the appropriate size of the outlet opening. The objective of this article is to determine the effect of the size of the discharge opening area (0.24–1.2 m²) and other factors on the obtained flow parameters (flow velocity, volumetric flow rate and static pressure value) generated by the two tested positive pressure ventilators. The volumetric flow rate was determined by measuring the flow velocity at appropriately selected measurement points. Two ventilator units were tested (one was the conventional type, while two were turbo). During the tests, the fans generated a flow of 4624.17 m³/h to 14,020.92 m³/h (the first—conventional type) and 4884.66 m³/h to 15,656.33 m³/h (the second—turbo type). The analysis carried out in the article can be used as a guideline for designers of buildings, with particular emphasis on cases in which the staircase is not directly adjacent to the façade wall (an escape route built into the axis of the building). Full article

The DSF (double-skin facade) system is an important element in building design and is used in adjacent spaces to control the inlet solar radiation, heat the air, reduce energy consumption, decrease the acoustics levels, and produce photovoltaic energy, among other improvements. The DSF system can, for example, be used in winter conditions to heat the air, which is then transported to non-adjacent spaces to improve the thermal comfort level and the indoor air quality that the occupants are subjected to. Smooth DSF systems, which are a focus in the literature, are subjected to higher solar radiation levels at a specific hour of the day. The semi-circular DSF system used in this work, which was built from a group of smooth DSF systems with different orientations, guarantees the reception of the highest incident solar radiation throughout the entire day. This work presents a numerical study of a new DSF system, called the semi-circular DSF. The DSF system consists of a set of 25 smooth DSFs with different orientations, each one consisting of an outer glazed surface and an inner surface provided by the outer facade of the auditorium, both separated by an air channel. In this work, the influence of the radius of the semi-circular DSF system and the opening angle of the DSF system on the thermal response of the auditorium was analysed. Thus, six auditoriums were considered: two sets of three auditoriums with radii of 5 m and 15 m, with each of the auditoriums having a different DSF opening angle (45°, 90°, and 180°). It was found that the greater the radius of the semi-circular DSF and the opening angle of the DSF system, the greater the area of its glazed surface and, consequently, the greater the availability of solar heating power. Therefore, during the occupation period, only the set of auditoriums with the largest semi-circular DSF radius managed to present acceptable levels of thermal comfort, which were verified from mid-morning until late afternoon. As for the opening angle of the DSF system, the influence was not very significant, although slight improvements in thermal comfort were noted when the value of this angle was reduced (see Case F as an example) due to the corresponding decrease in the volume of indoor air to be heated. In all auditoriums (see Case A to Case F), it was verified that the indoor air quality was acceptable for the occupants, so the airflow rate was adequately promoted by the ventilation system. Full article

The construction of flats is one of the steps toward fulfilling the need for housing in Jakarta and other big cities in Indonesia. This study investigated the thermal problems that focus on air movement in residential units of flats due to window dimensions that cannot accommodate the air velocity that surrounds the buildings because of monotonous window dimensions and the high elevation of the residential units. The position of the interest of this research is on the search for window dimensions that allow comfortable air movement in the residential unit. Based on these problems and interest, the pertinent issue is the design of window dimensions within the facades of the buildings according to the actual air velocity and the elevation of the residential units. The selected object of study was the Jatinegara Barat flats, a block of high-rise flats located in the middle of East Jakarta, Indonesia, which is adjacent to the river. We used a quantitative deductive methodology for the problem analysis via mathematical and simulation methods that use the Ansys R1 2020 software. The final results showed that the relationships between window dimensions, air velocity, and the elevation of residential units can be mapped horizontally and vertically by paying attention to the locations of the window openings with respect to the wind direction and building layout. The horizontal and vertical maps showed repetition of the window dimensions every four floors, with the four floors in the center of the building (read vertically) having window dimensions one-quarter smaller than the four floors above and four floors below. Full article