Search Results (27)

The increasing adoption of highly glazed façades in contemporary office building has improved daylight penetration but has also intensified glare risk and sunlight overexposure in Mediterranean climates, with direct implications for occupant visual comfort and environmental sustainability. While daylight optimization has been widely discussed, fewer studies have examined how façade morphology systematically shapes the balance between daylight sufficiency and visual comfort in Mediterranean island contexts. This study investigates the relationship between façade configuration, daylight availability, and glare performance in office buildings in Northern Cyprus using climate-based daylight simulation. Six façade morphologies are evaluated across a range of window-to-wall ratios (WWR) using EN 17037-aligned criteria and metrics, including spatial daylight autonomy (sDA), annual sunlight exposure (ASE), and daylight glare probability (DGP). Usable daylight is not simply a function of more glass. As WWR increases, fully glazed façades in Mediterranean conditions tend to admit excessive direct sun and intensify glare, so daylight becomes less workable even when illuminance is high. Instead, hybrid and adaptive morphologies that control lighting through a combined approach of shade, diffusion, and redirection provide the most dependable performance, reducing both overexposure and glare while ensuring sufficient daylight sufficiency. The findings also indicate a distinct turning point at about 50–55% WWR, beyond which performance is mostly dependent on the façade’s ability to modulate its morphology and further glass offers minimal advantage. Based on this, the article suggests a contextual framework to encourage façade options for Mediterranean office environments that are more sustainable, aesthetically pleasing, and climate-responsive. Full article

Daylighting is essential in residential building design because it influences energy efficiency and visual comfort while also supporting occupants’ health and overall well-being. Adequate natural light exposure aids circadian regulation and psychological restoration and enhances indoor environmental quality. This study examines how the window-to-wall ratio, skylight-to-roof ratio, and building orientation in a selected low-rise residential building can be optimized to ensure sufficient daylight in warm-humid climates. Using on-site illuminance measurements and climate-based simulations, the daylight performance is evaluated using metrics such as useful daylight illuminance, spatial daylight autonomy, and annual sunlight exposure. Results indicated that a 5% skylight-to-roof ratio (such as a 1:2 skylight setup), combined with a 22% window-to-wall ratio and glazing with a visible transmittance of 0.45, provides a balanced improvement in daylight availability for the chosen case study. The selected configuration optimizes spatial daylight autonomy and useful daylight illuminance while keeping annual sunlight exposure within recommended levels based on the surrounding building landscape. The findings emphasize the importance of tailoring daylighting strategies to site-specific orientation, glazing options, and design constraints. The approach and insights from this case study can be beneficial for incorporating into similar low-rise residential buildings in warm-humid contexts. Incorporating daylight-responsive design into urban and architectural planning supports several United Nations Sustainable Development Goals (SDG 3, 11, and 13). Full article

This research seeks to identify optimised screen façade patterns and ratios for the effective management of daylight ingress and glare effects. It employs generative adversarial networks (GANs) to generate pattern variations and further evaluates the resultant variations through daylight simulations for application in screen façades. The generated pattern data were classified by hierarchical clustering to distinguish distinct feature groups, and they were subsequently utilised as façade configurations. The pattern data were assessed through daylight performance metrics: spatial daylight autonomy (sDA), annual sunlight exposure (ASE), and daylight glare probability (DGP). The results of the annual-based simulations indicate that façade patterns with frame ratios in the range of 50–65% are useful in reducing the areas exposed to intensive glare on the façade side while maintaining the minimum required lighting conditions. The overall influence of screen façades on interior daylighting in a large space (e.g., 10 m × 10 m) was found to be limited. Their performance is notable in reducing glare discomfort areas within approximately 2.5 m of south-facing façades. This study supports an application strategy in which screen façades are used to manage the extent of areas exposed to daylight ingress within an interior space. Full article

Spatial Daylight Autonomy (SDA) and Annual Sunlight Exposure (ASE) are widely adopted metrics for daylight performance assessment in sustainable building design. While valuable, the complexity of these metrics, particularly due to the influence of indirect bounced light, makes them difficult to interpret, especially in high-density residential buildings with multiple apartment units. Additionally, the computational intensity of such analyses limits their practical use in early-stage design or unit comparison. As a result, potential residents often rely solely on direct sunlight exposure when evaluating units without access to meaningful comparative data. To address this gap, this study proposes a simplified daylight evaluation metric, termed the Annual Daylight Index, that is both intuitive and computationally efficient. The index is defined as the total number of annual sunlight hours received across all floor areas of a building, divided by the number of rooms. Implemented using visual programming within a BIM environment, the method leverages a reverse sunlight tracing approach. Its accuracy and efficiency were verified by comparing results and computation times against established daylight simulation tools. The resulting index enables both micro (unit-level) and macro (building-level) comparisons, offering a practical tool for designers, residents, and researchers engaged in daylight evaluation of multi-unit housing projects. Full article

This study examines the influence of vegetation on indoor daylight performance in school buildings located in the hot–humid climate of Chennai, India. With increasing urban development leading to the cutting or relocation of trees, their role in modulating interior daylight conditions has become critically relevant but remains underexplored in the literature. Recognizing a significant research gap in this area, this study employed a simulation-based approach using DesignBuilder 7.4 software. A government school in South Chennai, India, was chosen for this study. A total of 208 scenarios were generated by varying the window-to-wall ratio (WWR), facade orientation, floor level, and tree presence. Daylight performance was evaluated using spatial daylight autonomy (sDA), annual sunlight exposure (ASE), and useful daylight illuminance (UDI), based on IES LM-83-12 and LEED v4 standards. Simulation results showed that a 20% window-to-wall ratio (WWR) failed to meet daylight standards, while a 30–40% WWR with shading consistently performed well. Trees significantly improved daylight metrics, like sDA, UDI, and ASE, more so than orientation or floor level. This study urges regulatory mandates for climate-resilient schools, emphasizing fenestration and landscape integration. Full article

This study investigates the influence of façade-design parameters on daylighting performance in hot arid climates, with a particular focus on Egypt. A total of nine façade configurations of a residential building were modeled and simulated using Autodesk Revit and Insight 360, varying three critical variables: glazing type (clear, blue, and dark), Window-to-Wall Ratio (WWR) of 15%, 50%, 75%, and indoor wall finish (light, moderate, dark) colors. These were compared to the Leadership in Energy and Environmental Design (LEED) daylighting quality thresholds. The results revealed that clear glazing paired with high WWR (75%) achieved the highest Spatial Daylight Autonomy (sDA), reaching up to 92% in living spaces. However, this also led to elevated Annual Sunlight Exposure (ASE), with peak values of 53%, exceeding the LEED discomfort threshold of 10%. Blue and dark glazing types successfully reduced ASE to as low as 0–13%, yet often resulted in underlit spaces, especially in private rooms such as bedrooms and bathrooms, with sDA values falling below 20%. A 50% WWR emerged as the optimal balance, providing consistent daylight distribution while maintaining ASE within acceptable limits (≤33%). Similarly, moderate color wall finishes delivered the most balanced lighting performance, enhancing sDA by up to 30% while controlling reflective glare. Statistical analysis using Pearson correlation revealed a strong positive relationship between sDA and ASE (r = 0.84) in highly glazed, clear glass scenarios. Sensitivity analysis further indicated that low WWR configurations of 15% were highly influenced by glazing and finishing types, leading to variability in daylight metrics reaching ±40%. The study concludes that moderate glazing (blue), medium WWR (50%), and moderate color indoor finishes provide the most robust daylighting performance across diverse room types. These findings support an evidence-based approach to façade design, promoting visual comfort, daylight quality, and sustainable building practices. Full article

The growing number of daylighting metrics—often overlapping in scope or terminology—combined with the need for prior familiarization to interpret and apply them effectively, has created a barrier to their adoption beyond academic settings. Consequently, this study analyzes a representative set of established and emerging daylighting metrics to evaluate applicability, synergies, and limitations. Particular attention is given to their implications for occupant health, well-being, performance, and energy use, especially within the context of sensorless smart control systems. A virtual room model was simulated using DaySim 3.1 in two contrasting climates—Seville and London—with varying window-to-wall ratios, orientations, and occupancy schedules. The results show that no single metric provides a comprehensive daylighting assessment, highlighting the need for combined approaches. Daylighting Autonomy (DA) proved useful for task illumination, while Useful Daylight Illuminance (UDI) helped identify areas prone to excessive solar exposure. Spatial metrics such as Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) offer an overview but lack necessary granularity. Circadian Stimulus Autonomy (CSA) appears promising for evaluating circadian entrainment, though its underlying models remain under refinement. Continuous Overcast Daylight Autonomy (DAo.con) shows the potential for sensorless lighting control when adjusted for orientation. A nuanced, multi-metric approach is therefore recommended. Full article

In southern Hunan province, a vital element of China’s architectural cultural legacy, the quality of the indoor lighting environment influences physical performance and the transmission of spatial culture. The province encounters minor environmental disparities and diminishing liveability attributed to evolving construction practices and cultural standards. The three varieties of traditional residences in Shanggantang Village are employed to assess the daylight factor (DF), illumination uniformity (U0), daylight autonomy (DA), and useful daylight illumination (UDI). We subsequently integrate field measurements with static and dynamic numerical simulations to create a multi-dimensional analytical framework termed “measured-static-dynamic”. This method enables the examination of the influence of floor plan layout on light, as well as the relationship between window size, building configuration, and natural illumination. The lighting factor (DF) of the core area of the central patio-type residence reaches 27.7% and the illumination uniformity (U0) is 0.62, but the DF of the transition area plummets to 1.6%; the composite patio type enhances the DF of the transition area to 1.2% through the alleyway-assisted lighting, which is a 24-fold improvement over the offset patio type. Parameter optimization showed that the percentage of all-natural daylighting time (DA) in the edge zone of the central patio type increased from 21.4% to 58.3% when the window height was adjusted to 90%. The results of the study provide a quantitative basis for the optimization of the light environment and low-carbon renewal of traditional residential buildings. Full article

The atrium, as the core space of modern university libraries, is crucial for providing ample natural lighting and creating a comfortable spatial experience. It is also key to achieving the building’s green and low-carbon goals. However, designing the atrium of a university library faces a significant challenge: finding the right balance between ensuring good natural lighting and effectively reducing the energy consumption of the air conditioning system. This study aims to explore this balance and provide architects with various feasible design schemes. Firstly, a parametric typical model of the atrium space was established by researching 36 university libraries. Based on the Grasshopper platform in Rhino, the typical model was simulated for natural lighting and energy consumption, and the Wallacei plugin was used to couple the optimization parameters of the typical model with the optimization target parameters. The multi-objective optimization experiment of the typical model was carried out with the objectives of maximizing spatial daylight autonomy and the percentage of useful daylight illuminance, as well as minimizing air conditioning energy consumption. The experiment generated 2000 optimization solutions, and the analysis of the historical solution set revealed the complex non-linear relationship between optimization parameters and performance indicators. Moreover, three Pareto optimal solutions were selected as representative design schemes, providing valuable references for architects when designing the spatial form of the atrium. Full article

Since individuals with severe and profound Intellectual Disabilities (IDs) have no concept of time, it is difficult for them to autonomously maintain daily structures. Those affected are dependent throughout their lives on external care structures. Even though research suggests that individuals with IDs should live in smaller facilities, individuals with higher support needs are more likely to be placed in large institutions and clustered group homes. The aim of this study was to define design criteria and test their applicability to a residential building design whose architecture enables individuals with IDs to develop autonomy through spatially experienced temporality. Qualitative data was collected in a mixed method evidence-based design approach: systematic behavioural observations, structured interviews, focus groups, and the UV-index method. Four design criteria could be described that contribute to an autonomy-promoting temporality: (a) spatial sequencing and repetition, (b) privacy-related variation of spatial dimensions, (c) spatial orchestration of daylight, and (d) constant emotional proximity to the caregiver. The hypothesis of using architecture to promote temporality in clients with IDs and Challenging Behaviour (CB) has proven to be potentially effective in designing a therapeutic environment. Our findings provide valuable data on how long-stay facilities should be designed in the future. Full article

After the pandemic, as it becomes more feasible to study and work from home, the quality of residential daylighting has attracted increasing attention. With the rapid growth of high-density residential areas, China is confronted with the incoordination between site planning and interior daylight availability across a wide region. Therefore, this paper investigates the applicability of planning regulations for daylight availability in dense residential areas under different climates across China, with the aim of providing data to optimize design strategies. ClimateStudio and ALFA were used to calculate the daylight factor (DF), daylight illuminance, spatial daylight autonomy (sDA), useful daylight illuminance (UDI), and melanopic equivalent daylight illuminance (m-EDI) of living rooms in four practical mixed housing estates in different Chinese daylight climate zones. The results showed that most of the studied units failed to meet current standards of DF and sDA_300,50% for residence. However, more than half of these units still had high potential for UDI and met the recommendation of m-EDI by daylight only. The results verified the importance of integrative consideration of the local daylight climate and interior unit design for residential area layout planning. Finally, this paper suggests two topics for further exploration to bridge the gap between area planning and interior daylight availability in dense residential areas. Full article

This paper introduces a comprehensive methodology for creating diverse layout generation configurations, aiming to address limitations in existing building optimization studies that rely on simplistic hypothetical buildings. This study’s objective was to achieve an optimal balance between minimizing the energy use intensity (EUI) in kWh/m², maximizing the views percentages to the outdoor (VPO), achieving spatial daylight autonomy (sDA), and minimizing annual sunlight exposure (ASE). To ensure the accuracy and reliability of the simulation, the research included calibration and validation processes using the Ladybug and Honeybee plugins, integrated into the Grasshopper platform. These processes involved comparing the model’s performance against an existing real-world case. Through more than 1500 iterations, the study extracted three multi-regression equations that enabled the calculation of EUI in kWh/m². These equations demonstrated the significant influence of the window-to-wall ratio (WWR) and space proportions (SP) on the EUI. By utilizing these multi-regression equations, we were able to fine-tune the design process, pinpoint the optimal configurations, and make informed decisions to minimize energy consumption and enhance the sustainability of residential buildings in hot arid climates. The findings indicated that 61% of the variability in energy consumption can be attributed to changes in the WWR, as highlighted in the first equation. Meanwhile, the second equation suggested that around 27% of the variability in energy consumption can be explained by alterations in space proportions, indicating a moderate correlation. Lastly, the third equation indicated that approximately 89% of the variability in energy consumption was associated with changes in the SP and WWR, pointing to a strong correlation between SP, WWR, and energy consumption. The proposed method is flexible to include new objectives and variables in future applications. Full article

According to relevant statistics, the electricity consumption for lighting in university buildings accounts for 20 to 40% of the total energy consumption of the buildings. Lighting energy saving is a key influential factor in achieving a low-carbon campus construction. The electricity consumption for lighting is simultaneously affected by the utilization of natural daylight and artificial lighting schemes. Currently, there is a lack of research regarding the dynamic quantitative correlation between the geometric design of external windows affecting the utilization of natural daylight and carbon emissions. Also, research on the dynamic synergistic impact between natural light utilization and artificial lighting on carbon emissions has not been observed. Hence, there is a lack of quantitative carbon impact prediction and guidance in the early design and actual operation of such spaces. This study took the professional drawing space of a university in the severe cold regions of Shenyang as a prototype. Daylight factor (DF) and spatial daylight autonomy (sDA) were determined using Rhino + Grasshopper and Ladybug + Honeybee for window geometry. DIALux evo simulation was used to analyze the carbon emissions of space operation, followed by correlation analysis and multiple linear regression analysis using SPSS to determine the degree of influence of each window design parameter on the carbon emissions. The window-to-floor ratio (WFR), window-to-wall ratio (WWR), windowsill height (H_ws), window width (W_w), and window height (H_w) had inhibitory effects on carbon emissions from daylight-responsive artificial lighting (C), and the influence of different orientations was different. Under the condition of an opposing window, the overall C trend of the professional drawing space was west < east< south < north, and the C of the morning period in each orientation was significantly lower than that in the afternoon period. Taking the frame structure system space with a floor-to-floor height of 4.2 m as an example, within the requirements of WFR and WWR, the C of the west-facing professional drawing classroom with 2.55 m for H_w, 0.75 m for H_ws, and 9.6 m for W_w was the smallest. To a certain extent, opening large windows and opening high windows can reduce the C of the space. Full article

This paper presents the results of a study that developed improved inverse models to accurately predict the annual daylighting performance (sDA and lighting energy use) of various window configurations. This inverse model is an improvement over previous inverse models because it can be applied to variable room geometries at different weather locations in the US. The room geometries can be varied from 3 m × 3 m × 2.5 m to 15 m × 15 m × 10 m (length × width × height). The other variables used in the model include orientation (N, E, S, W), window-to-floor ratio, window location in the exterior wall, glazing visible transmittance, ceiling visible reflectance, wall visible reflectance, shade type (overhangs, fins), shade visible reflectance, lighting power density (LPD) (W/m²), and lighting dimming setpoint (lux). Such models can quickly advise architects during the preliminary design phase about which daylighting design options provide useful daylighting, while minimizing the annual auxiliary lighting energy use. The inverse models tested and developed were multi-linear regression (MLR) models, which were trained and tested against Radiance-based annual daylighting simulation results. In the analysis, 482 cases with different model conditions were simulated, to develop and validate the inverse models. This study used 75% of the data to train the model and 25% of the data to validate the model. The results showed that the new inverse models had a high accuracy in the annual daylighting performance predictions, with an R² of 0.99 and an CV(RMSE) of 15.19% (RMSE of 58.91) for the lighting energy (LE) prediction, and an R² of 0.95 and an CV(RMSE) of 14.38% (RMSE of 8.02) for the sDA prediction. In addition, the validation results showed that the LE MLR model and sDA MLR model had an R² of 0.96 and 0.85, and RASE of 121.89 and 8.54, respectively, which indicate that the inverse models could accurately predict daylighting results for sDA and lighting energy use. Full article

Architects face the challenge of exploring various design solutions in the early design stage, often with conflicting optimization goals. To tackle this complexity, they need to rely on tools and methodologies during the conceptual phase to assess and optimize designs, considering multiple aspects of building performance. Parametric Design, Generative Design, and automation in Building Information Modelling (BIM) offer architects new opportunities to work on complex buildings. These advancements empower designers to enhance their designs, increase project efficiency, improve performance, and reduce project time and costs. Multi-Objective Optimization algorithms are employed to address conflicting objectives in the design process. The GENIUS project introduces an Algorithm-Aided Design workflow that optimizes the building shape and Window-to-Wall Ratio of an office building, considering energy and daylight performance. The integration of BIM software, visual programming tools, and Artificial Intelligence techniques (Genetic Algorithms and RBFOpt model-based optimization) allows architects to identify optimal solutions aligning with design objectives. The workflow was validated through a case study of a large office building, focusing on maximizing daylight performance using the Spatial Daylight Autonomy metric and minimizing energy consumption using the Energy Use Intensity metric. The GENIUS project equips architects with a methodology and toolset to improve their designs and identify optimal solutions for complex design challenges. Full article