Search Results (33)

In single-aspect studio apartments, daylight sufficiency and sunlight exposure constrain window design simultaneously. A studio reference room in Bangkok, Thailand was evaluated using Radiance through Ladybug Tools and a TMYx weather file. Six main-window configurations, three visible-light transmittance (VLT) levels (0.45, 0.65, 0.88), and four orientations formed a complete factorial set of 72 cases, assessed with spatial daylight autonomy (sDA_300/50%), useful daylight illuminance (UDI_100–3000), and annual sunlight exposure (ASE_1000,250). The room was also simulated with the balcony door alone, giving a simulated baseline. Within the investigated design space, orientation accounted for 93.16% of the variation in ASE and 63.36% in UDI, but only 3.39% in sDA, which was governed instead by VLT (69.10%) and window configuration (23.23%). sDA ranged from 52.17% to 100.00% and 19 cases did not reach 75%; ASE ranged from 1.09% to 53.26%. The door alone gave a mean sDA of 47.10%, and the smallest window raised it by 25.00 percentage points. A screening rule informed by LEED v5 retained 29 cases and no west-facing case; substituting finer-grid values for four near-threshold cases reduced this to 28, testing that subset rather than grid independence across the dataset. Orientation and solar exposure should be assessed first, transmittance second, and window area last. Full article

In the hyper-arid climate of Riyadh, Saudi Arabia, the building envelope is a critical determinant of energy demand and occupant comfort. This paper reports an experiential-learning experiment in which undergraduate architectural-engineering students applied building performance simulation (BPS) as a generative design instrument rather than a post-design audit tool to their own real capstone building, a 6581 m² mixed-use development. Using Sefaira (EnergyPlus/Radiance engines), they iteratively diagnosed, tested, and refined envelope decisions against the prescriptive thresholds of the Saudi Building Code (SBC 601). A baseline analysis revealed a high Energy Use Intensity (EUI) of 139 kWh/m²·yr, driven primarily by solar heat gains and an “overlit” floor plate that exceeded Annual Sunlight Exposure (ASE) thresholds. Students then implemented passive interventions—improved glazing U-value (0.50 W/m²·K), reduced Solar Heat Gain Coefficient (SHGC 0.20), and external shading fins. These produced a 6.95% EUI reduction (139→130 kWh/m²·yr) and a 17.24% fall in cooling energy. The energy outcomes are consistent with established findings for hot-arid envelopes and are therefore treated here not as the novelty but as the technical evidence the students generated. Daylighting analysis confirmed improved distribution and reduced glare risk, although ASE remained above the LEED v4 threshold. The contribution is pedagogical: the study documents a replicable framework through which a design studio develops students’ technical competence in performance-driven envelope design, evidenced by their progression from uninformed parameter selection to code-referenced design reasoning and by the difficulties and trade-offs they encountered. Full article

Narrow internal lightwells are often featured in multi-story residential buildings in hot arid climates in order to daylight rooms where direct façade access is not possible, but privacy-driven window closure strongly limits the daylighting potential of these shafts. This paper examines whether three retrofit daylighting strategies—(1) increased shaft wall reflectance, (2) multi-level tubular daylighting devices (MTDDs), and (3) inclined lightwell remodeling with clerestory openings—can retrofit a common residential lightwell in Ha’il City, Saudi Arabia for high performance, high-efficiency daylighting performance under typical privacy-constrained urban conditions. A calibrated daylight model was developed using field measurements of the existing lightwell conditions, and the three retrofit strategies were then evaluated through Radiance-based simulations. The calibrated Radiance model showed good agreement with observations (MBE = −9.6%, RMSE = 17%). It was found that the aged lightwell received less than 0.5% of outdoor daylight in clear summer conditions and that the performance was highly seasonal and orientation-dependent, with 15–20% higher summer peaks in one monitored room, while both rooms remained largely below 100 lx in winter and overcast periods. Simulations determined that the base case results in the ground and first-floor areas remaining comparatively lowly illuminated (UDI_{<100 lx} = 96–100%). The wall reflectance contributed only moderate improvements, while the MTDD strategy was notably effective in improving the daylight availability of lower-floor levels without increasing annual sunlight exposure. The biggest gains (first-floor mean illuminance increasing to 516–952 lx and 100% sDA_300,50% on the second floor) were for the lightwell inclined with clerestory opening type, but an increased risk of over-exposure at upper levels was activated. These findings demonstrate how balancing the needs of daylight autonomy with exposure control shapes the performance of daylight retrofits. Full article

Improving daylight performance in heritage hotels is essential for enhancing comfort, quality, and energy efficiency, especially in hot-desert climates where solar availability must be balanced with glare and overheating risks. However, façade preservation requirements limit conventional daylighting interventions, creating a need for climate-responsive and conservation-compatible solutions. This study investigates daylight optimization strategies for the Transatlantique Hotel in Biskra, Algeria, using Climate-Based Daylight Modelling (CBDM). The methodology combines three-dimensional modelling, in situ material characterization, and Radiance-based simulations with ClimateStudio version 2.3. Daylight performance was assessed using Spatial Daylight Autonomy (sDA), Annual Sunlight Exposure (ASE), Useful Daylight Illuminance (UDI), and Daylight Factor (DF). Tested scenarios included improved glazing transmittance, increased surface reflectance, and tubular daylighting devices (TDDs). Results show that the existing configuration provides insufficient daylight in guest rooms, with average illuminance in poorly performing rooms ranging from 140 to 310 lux. Material-based optimization increased Room 210’s sDA from 3.9% to 62.3%, representing an approximately +1497% relative improvement, while UDI reached 58.6%. TDDs produced the strongest improvement: Room 110 sDA increased from 11.8% to 82.4% (+598%), while ASE decreased from 10.6% to 0.0%; Room 310 sDA increased from 31.2% to 100% (+221%), while ASE decreased from 16.9% to 0.0%. The novelty lies in integrating material-based and TDD strategies under strict façade-preservation constraints in a hot-desert heritage hotel. Full article

This study investigates the integration of a multi-configuration parametric shading system in buildings with continuous ramp designs to enhance daylight performance and visual comfort. Focusing on the Harbourside Art Museum in Bristol, UK, the research explores how discrete-configuration parametric façade configurations can be optimized to balance daylight access and glare control in complex spatial environments. A parametric simulation workflow was developed using Rhino, Grasshopper, Ladybug, and Honeybee, supported by Radiance and Daysim engines for Climate-Based Daylight Modelling (CBDM). Three performance metrics—Useful Daylight Illuminance (UDI), Annual Sunlight Exposure (ASE), and Daylight Glare Probability (DGP)—were employed to evaluate baseline and optimized models. Optimization was performed using Galapagos (single-objective genetic algorithm, population size = 50 individuals, 100 generations, convergence tolerance = 0.001; the fitness function maximized UDI while penalizing ASE excess above 75 h/year and GFI below 0.75, using a weighted single-objective score: Fitness = UDI − 0.3 × (ASE/250) + 0.3 × GFI) and Colibri 2.0 combined with Design Explorer for exhaustive multi-objective combinatorial analysis. Results from the base model showed high daylight availability but excessive glare, particularly along the ramp. Through systematic optimization, the study identified façade and contextual configurations that achieved a UDI of 0.77, an ASE of 74, and a glare-free index of 0.81. The findings demonstrate that orientation-specific multi-configuration shading, when integrated with contextual design parameters, significantly improves the daylighting performance of architecturally complex spaces. This research offers a replicable methodology for designers aiming to integrate responsive daylighting strategies in public and exhibition buildings. Full article

This study presents a coupled building simulation framework that evaluates thermal and daylight performance concurrently within a unified multi-objective decision space. Unlike conventional sequential workflows, where daylight metrics are assessed after energy optimization or used primarily for compliance verification, the proposed approach embeds EnergyPlus and Radiance simulations directly within the same optimization loop. This structure enables a systematic exploration of non-linear interactions between Energy Use Intensity (EUI), cooling loads, Spatial Daylight Autonomy (SDA), and Annual Sunlight Exposure (ASE) during early-stage façade design. The framework is demonstrated through a medium-rise office building in India’s National Capital Region, a composite climate characterized by strong seasonal and directional variability. Parametric variation in façade orientation, window-to-wall ratio, and external shading configurations was explored using a multi-objective genetic algorithm to identify Pareto-optimal performance regimes. The results reveal distinct orientation-dependent trade-off structures between solar exposure, cooling demand, and daylight availability that are not evident in rule-based or sequential simulation approaches. In particular, a transitional East-facing façade regime emerges in which balanced shading and glazing proportions achieve near–North-facing cooling performance while maintaining high daylight autonomy under controlled sunlight exposure. Rather than proposing a single optimal solution, the study demonstrates how tightly coupled thermal–daylight simulation can function as a knowledge-discovery tool, enabling the extraction of transferable façade response patterns from simulation outputs. The findings highlight the limitations of prescriptive orientation hierarchies in composite climates and illustrate the value of integrated simulation workflows for performance-driven early-stage design across diverse climatic contexts. Although the study references thermal performance, the optimization objectives are limited to peak cooling load and annual Energy Use Intensity (EUI). Occupant comfort indices such as Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD) were not explicitly simulated. Therefore, results are interpreted as energy–daylight performance optimization rather than direct thermal comfort optimization. Full article

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

Two prototype moss-based green roof systems were developed and evaluated using a newly cultivated strain of Racomitrium japonicum (Dozy & Molk.) to investigate their feasibility in mitigating rooftop heat and enhancing carbon sequestration under actual urban conditions. Flat and sloped-type green roof systems (2 m × 2 m each) were developed and installed on a rooftop to investigate their performance in summer (from June to August 2025). The moss-based systems reduced rooftop surface temperature by an average of 6–10 °C during daytime and retained approximately 1.5–2.5 °C of heat at night, thereby contributing to cooling and thermal buffering. The moss layer effectively reduced solar radiation heating of the underlying soil. Despite exposure to intense sunlight and high summer temperatures, the moss maintained a consistent growth rate of 3–5 mm per month. The annual carbon sequestration capacity of the prototype system was estimated at approximately 0.3 kg C/m².year, which is comparable to values reported for other vegetation types. These findings indicate that moss-based green roofs incorporating the newly cultivated moss strain have practical potential for urban heat island mitigation and carbon capture. 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

Centralized daylight control has been extensively studied for its ability to optimize useful daylight while mitigating glare in targeted areas. However, this approach lacks a comprehensive visual comfort framework, as it does not simultaneously address spatial glare distribution, uniform high useful daylight levels across all sensor points, and overheating prevention through regulated annual solar exposure. Nevertheless, decentralized control facilitates autonomous operation of the individual façade components, addressing all the objectives. This study integrates a biomimetic functional approach with building performance simulations by computational design to evaluate different kinetic façade configurations. Through the implementation of parametric modeling and daylight analysis, we have identified an optimal angular configuration (60° for the focal region, 50° for the non-focal region) that significantly increases building performance. The optimized design demonstrates substantial improvements, reducing excessive sunlight exposure by 45–55% and glare incidence by 65–72% compared to other dynamic solutions. The recommended steeper angles achieve superior performance, maintaining high useful daylight illuminance (UDI > 91.5%) while dramatically improving visual comfort. Sensitivity analysis indicates that even minor angular adjustments (5–10°) can induce a 10–15% variation in glare performance, emphasizing the necessity of precise control mechanisms in both focal and non-focal regions of the façade. These findings establish a framework for creating responsive building façades that balance daylight provision with occupant comfort in real-time operation. Full article