Daylight Availability Research Articles

Automation and optimization in daylight analysis and life cycle assessment for automated daylight monitoring device for a metro rail station box in Ahmedabad, India

Daylight analysis and optimization are pre-requisites for energy-efficient and sustainable infrastructure. Conventional practices of designing and providing artificial lighting often ignore the consideration of the availability of natural daylight for the infrastructure. This paper aims to analyze the availability and potential of natural daylight reviewing the sky component type at a designated location, real-time sensor-based illuminance measurement on-site and BIM-based daylight simulation. Consequently, a sensor prototype was deployed to the metro rail station for automated optimization. Firstly, the sky component type of Ahmedabad was determined based on the literature review. Subsequently, sensors were integrated at the strategic grid point location covering the entire metro rail station to collect real-time Illuminance for daylight factor calculation. Furthermore, BIM-based sun path and shadow analysis and daylight simulation were carried out to suggest the possibility and potential of daylight savings. Finally, based on all the analysis and results, a newly designed sensor-based prototype was developed and equipped to enhance automated optimization for daylight savings, which resulted in 29% energy savings monthly. This approach significantly helps the project stakeholders to enhance building energy performance and lead a step closer towards sustainable infrastructure.

A comprehensive study of how urban morphological parameters impact the solar potential, energy consumption and daylight autonomy in canyons and buildings

Over the past two decades, global greenhouse gas emissions have surged, leading to rising sea levels and climate change. Solar energy has emerged as an excellent solution to this problem. This study aims to assess daylight availability and energy consumption in urban canyons and blocks in a semi-arid climate while exploring the correlation between the heterogeneity of urban morphological parameters and key research variables. The study employed field measurements and simulations using Ladybug Tools and UMI. Data were collected from urban canyons and blocks in three areas, amounting to 1,366,982 m2. The findings indicate that areas with abundant greenery and H/W ratios exceeding 1.8 experience the most significant shading effects in urban canyons. Selecting suitable trees and placing them in strategic locations can enhance energy efficiency. Furthermore, broad urban canyons (H/W < 0.5) receive four times more solar radiation than narrow urban canyons (H/W > 1.8) with high tree density, peaking at 240 kWh/m2 during summer. In urban blocks, rooftops have the highest solar potential, with imbalances between building heights and interbuilding shading as factors that reduce solar capabilities. Tree coverage significantly affects the solar potential of facades, with some urban blocks receiving less than 5,000 kWh/m2 of solar radiation on the southern facades each month. Finally, this study examined the impact of heterogeneity within urban morphological parameters on the principal research variables. The results indicate that the heterogeneity observed in urban morphological parameters affects daylight availability and energy consumption within urban blocks.

Should Danish building regulations legalise basement dwellings? – Consequences for daylight and view out investigated through case studies

Densification of cities is ongoing for sustainability purposes, but it has consequences for daylight availability in dwellings and the view out. Despite 'comparable conditions', national daylight and view-out regulations differ between Nordic countries, particularly regarding allowing dwellings below ground level. Two case studies investigate daylight and view-out access in modelled basement dwellings through simulations of daylight autonomy and renders of view-out content. Results indicate that basement dwellings can meet daylight and view-out access requirements in suburban, low-rise neighbourhoods but cannot meet the requirements in medium- to high-rise urban contexts. This study will contribute to future political decisions on national building regulations in Denmark and may influence future decisions on urban planning and building development.

Enhancing Daylight Availability in Historical Buildings through Tubular Daylight Guidance Systems: A Simulation-Based Study

This simulation-based study investigates the potential of tubular daylight guidance systems (TDGS) to enhance daylight availability in historical buildings. Historical buildings often face challenges in providing sufficient daylight to non-lit areas without altering the building’s facade. TDGS offer a passive, building-integrated solution that redirects daylight to target areas while preserving the building’s originality. The study focuses on a historic passage building without ground floor openings and aims to improve visual comfort and daylight availability. Climate Studio software is used to assess the current daylighting conditions and to simulate various scenarios for TDGS implementation. The study considers four TDGS alternatives with different diameters, evaluating their impact on useful daylight illuminance (UDI) and spatial daylight autonomy (sDA). The findings reveal significant increases in UDI and sDA, ranging from 68.7 % to 403.7 %, and from 79.9 % to 1813.6 %, respectively, depending on the tube diameter. These results underscore the importance of daylight tube diameter in increasing the availability and distribution of useful daylight. The study emphasizes the potential of TDGS to optimize daylighting experiences in historical buildings with limited daylight

Analysing the Daylighting Performance of the Main Prayer-hall in the Great Mosque of Hama, Syria

Daylighting and solar availability at urban scale has come to play a crucial role in the perception of discomfort conditions for people, both in outdoor and indoor spaces, and on the energy consumption of buildings. Daylighting and solar analyses are typically done separately. The paper presents a novel method, called the ‘sunlight-daylight signature’ (SDS), which allows the qualitative analysis of urban settings with respect to sunlight and daylight. The method can be used to classify different urban settings in terms of daylight/sunlight access or to test new development proposals by referring to existing locations and confirm whether a certain daylight quality is met. The SDS relies on a new analysis tool, called ‘sunlight-daylight wedge’ (SDW), which combines obstruction (through the vertical sky component VSC) and sunlight access (through the annual probable sunlight hours PASH and the winter probable sunlight hours PWSH). The orientation of the façade at each point is also included as it will affect the times of the day when the sun-hours from PASH and PWSH occur, thus affecting the character of the corresponding sunlight. The SDS approach is based on a clustering technique to subdivide large datasets (in this case, daylight data points across entire cities or major urban areas) into smaller groups, using machine learning by way of the k-medoids clustering technique. This is used to derive typical daylight and sunlight scenarios representing groups of data points with similar conditions. Additional data is included to account for urban density and daylight availability in public areas. Final output of the clustering process consists of a map showing areas with the same daylight signature (SDS), which means areas with the same sunlight and daylight conditions. The SDS can be useful for urban planners and building practitioners to predict the access to both daylight and sunlight of large urban settings to optimize comfort for people and energy usage.

The impacts of urban canyons morphology on daylight availability and energy consumption of buildings in a hot-summer Mediterranean climate

Proper sunlight access has a positive impact on the physical and mental health of citizens, as well as on reducing energy consumption. This capacity may be limited by inappropriate urban morphology, and urban canyons and buildings are deprived of proper daylight. The purpose of this research is to study the current solar potential on the surface of the canyons and buildings and the effect of urban morphology parameters on the amount of each of the main variables of the research in Ilam, Iran. First, solar radiation, daylight illuminance, and air temperature were measured at different points of the studied canyons for three days. After that, the studied area was modeled with Rhino-Grasshopper software, and simulation was done using Ladybug Tools and UMI plugin. The results showed that the amount of daylight available in most canyons is low. Less than 30 % of the canyon’s surfaces benefited from 6 h of direct sunlight during the measurement. The simulation results for the 62 studied buildings showed that the highest amount of daylight is related to buildings with a height of more than 10 m. 56 % of the buildings had an annual solar radiation of less than 500 mw/m2. The roofs of the buildings received the most radiation, accounting for 72 % of the total radiation. By examining the parameters of urban morphology, it was found that the most influential parameter on the amount of solar radiation was the floor area, and the height of the buildings had the most influence on energy consumption.

Simulating the annual energy demand to meet non-visual health recommendations from a luminaire level lighting control system

This paper introduces a digital simulation workflow that calculates annual eye-level illuminance and energy demand from daylight and electric lighting sources for an array of view positions across 9-channels of spectral data. This Radiance-based workflow combines parts of the LARK spectral lighting code to offer better spectral resolution and accuracy when computing melanopic lx to evaluate the non-visual health potential for view positions within a digital model. The authors have implemented a series of annual climate-driven simulations and post-processed time-series of resulting data using the R statistical analysis software to compute Equivalent Melanopic Lux (EML) and energy demand (kWh) for an array of view positions and view directions in a digital model. This allows us to compute the energy demand of a given lighting and shading control scenario, which is optimized by hourly daylight availability to meet a recommended level of melanopic lx. This combined workflow uses digital models of an interior space to evaluate the annual potential of non-visual light exposure under different architectural, lighting, and shading control scenarios. This paper demonstrate the utility of this workflow by evaluating a luminaire-level lighting controls (LLLC) system to meet eye-level light exposure recommendations from the WELL Building Institute Feature L03 Circadian Lighting Design and compare the energy demand between targeted melanopic lux thresholds and shading control scenarios.

Energy efficiency of commercial offices by luminous retrofit

Lighting is one of the systems that mostly consume electricity in commercial buildings. Therefore, improving its efficiency has the potential to reduce electricity consumption and emission of polluting gases. The objective of the present study was to assess an office lighting system retrofit of an existing building from the 1990s, verify the light levels in relation to standards of the Brazilian requirements, and to explore new systems with potential for luminous and energy improvement. The analyzes were carried out through computer simulations using the DIALux evo software, which allows the evaluation of artificial and natural illuminations simultaneously. The results indicated that the existing lighting system does not meet the average illuminance standard value for office environment. From simulations with new arrangements and types of luminaires and lamps, two more efficient lighting systems were designed. The first presented savings of 15.5% in lighting energy when replacing T12 fluorescent lamps with LED luminaires. The second system considered the use of natural light and was complemented by artificial lighting with the aid of a dimming system linked to the availability of daylight, and presented up to 67% less electric energy consumption when compared to the existing lighting system in the environments. Therefore, it was possible to propose actions to the existing lighting system retrofit and, thus, offer better visual comfort to users and at the same time save energy.

Daylight Analysis in Terms of Building Direction and One-Way Roof

The location of the buildings in the residential area is very important in protecting or benefiting from sunlight. The dynamic structure of the sun, which constantly changes according to time and seasons, directly affects the building's architecture and urban formation. Ignoring the sun's use of the structures during the construction of the buildings can cause significant disturbances to the residents. Daylight strategies, which are also influenced by climate, depend on the availability of natural light, determined by the latitude of the building site and the instantaneous conditions around the building. High latitudes have different summer and winter conditions, with lower daylight levels in winter. At these latitudes, designers often aim to maximize daylight penetration in buildings. In the tropics, where daylight levels are high throughout the year, the design emphasis is often on preventing overheating by limiting the amount of sunlight entering the building. Daylight availability depends not only on latitude, but also on the orientation of a building, and each facade and material of the building requires a different design importance. Therefore, daylight and architectural design strategies are two inseparable phenomena. In this respect, examining traditional architecture and successful natural lighting designs in the past is very useful for understanding climate-balanced building design. For this purpose, determining the roof slope according to the sun angle in architectural structures by calculating according to the location provides efficiency in many issues from energy efficiency to human health.

Sunlight-Daylight Signature: a Novel Concept to Assess Sunlight and Daylight Availability at Urban Scale

Daylighting and solar availability at urban scale has come to play a crucial role in the perception of discomfort conditions for people, both in outdoor and indoor spaces, and on the energy consumption of buildings. Daylighting and solar analyses are typically done separately. The paper presents a novel method, called the ‘sunlight-daylight signature’ (SDS), which allows the qualitative analysis of urban settings with respect to sunlight and daylight. The method can be used to classify different urban settings in terms of daylight/sunlight access or to test new development proposals by referring to existing locations and confirm whether a certain daylight quality is met. The SDS relies on a new analysis tool, called ‘sunlight-daylight wedge’ (SDW), which combines obstruction (through the vertical sky component VSC) and sunlight access (through the annual probable sunlight hours PASH and the winter probable sunlight hours PWSH). The orientation of the façade at each point is also included as it will affect the times of the day when the sun-hours from PASH and PWSH occur, thus affecting the character of the corresponding sunlight. The SDS approach is based on a clustering technique to subdivide large datasets (in this case, daylight data points across entire cities or major urban areas) into smaller groups, using machine learning by way of the k-medoids clustering technique. This is used to derive typical daylight and sunlight scenarios representing groups of data points with similar conditions. Additional data is included to account for urban density and daylight availability in public areas. Final output of the clustering process consists of a map showing areas with the same daylight signature (SDS), which means areas with the same sunlight and daylight conditions. The SDS can be useful for urban planners and building practitioners to predict the access to both daylight and sunlight of large urban settings to optimize comfort for people and energy usage.

Ideal thermochromic smart window in a south-facing office room of China considering daylighting and energy performance

ABSTRACT Thermochromic (TC) smart window which allows modulating the transmission of solar heat energy and sunlight in response to environmental conditions has great potential for improving the building energy and daylighting performance simultaneously. In this study, the multi-objective optimization method is used to determine the ideal optical properties of TC windows. Parametric assessment is firstly conducted to investigate the influence of several crucial parameters. Multi-objective optimization is then carried out by applying Non-dominated Sort Genetic Algorithm-III, maximizing daylight availability and building energy efficiency. Finally, the decision-making of the Pareto frontier is performed to achieve the ideal TC windows in 32 representative cities in different climatic zones of China. Results demonstrate that increasing the luminous transmittance at low-temperature and decreasing luminous transmittance modulation ability are beneficial to daylighting and energy performance. Lower solar transmittance at low-temperature contributes to building energy savings in Beijing, Shanghai, Guangzhou and Kunming, except for Harbin. Higher solar transmittance modulation ability is desired for building energy efficiency. The optimum value for the transition temperature is in the range of 23.67–38.85°C. The building energy consumption can be reduced by 13.01%, and the desired daylighting hours can be improved by 8.90%, relative to the clear double-glazed windows.

Façade design of side-lit spaces for different climates and surroundings by machine learning and NSGAIII

This work aims to propose a simplified decision tool for the design of side-lit spaces that accounts for the impacts of climate and surroundings. The framework was developed using a smart optimization algorithm NSGA-III in combination with CatBoost ensemble machine learning technique and simulation. WWRs and overhang depths were optimized to maximize daylight penetration, minimize glare risk and reduce energy demand in different climates, orientations, space proportions, and surrounding obstruction angles. Besides, optimal solutions were used to determine the range of attainable targets for daylight, glare, and energy metrics in each climate, which can be used as requirements of national codes and standards. For example, for WDR = 3:2 and an OA of 20, energy demand varied between 260 and 266 kWh/m2, ASE remained at 40–50%, and sDA was reported 100% for south-oriented cases in Tehran. A sensitivity analysis was also performed to provide insights into how various design parameters affected daylight and energy performance in architectural spaces. The results revealed that daylight availability metrics were highly sensitive to the Window-to-Wall Ratio (WWR), while glare metrics were primarily affected by obstruction angle. Energy consumption was mainly influenced by room depth, WWR, window orientation, and obstruction angle. Notably, these parameters ranked similarly across all considered climates, albeit with varying degrees of significance. Results were presented in the form of guide charts that offer a practical tool for designing buildings in highly obstructed contexts and enable non-programmer architects and designers to make informed decisions.

A design methodology to consider occupants’ spatial adjustment and manage view content in adaptive façade design for improving visual comfort

ABSTRACT Occupants’ spatial adjustment (OSA) is one of the critical adaptive behaviours in buildings because it affects occupants’ comfort and contents of view. However, OSA for contents of view management from facade (e.g. sky, other construction, and greenery) have not been quantified to be integrated into other aspects of multi-objective building design, particularly façade design. The current study develops a design methodology and a correspondent plugin tool to incorporate OSA and content view calculation for visual comfort improvement. To this end, first, a test cell and outdoor and indoor environment were modelled, and façade geometric variables and OSA variables (location and direction of occupant’s sight) were set. After that, images were captured from hypothetical occupants’ locations inside in different directions of sight while façade transformation alternatives were recorded to the occupants’ content view images. Next, python image processing was linked to the Grasshopper modelling environment for content view analysing and quantification to be integrated into the optimisation process linked with visual comfort objectives. The designed methodology helped improve occupants’ visual comfort by optimising façade form and managing OSA for optimum daylight availability, glare minimisation, and enhancing occupants’ content view. Illuminance and discomfort glare probability (DGP), useful daylight illuminance (UDI), and spatial daylight autonomy (sDA) were used to shed light on the daylight performance of the proposed scenarios. Results demonstrated that a unique OSA and integrated façade configuration at any point in time and seasons that are suitable for the occupant’s daylight availability management, decreases perceived glare, and enhances the content view.

Reducing Lighting Energy Use in Controlled Agricultural Environments

Photometric simulations using both daylight and electric lighting were performed to compare the energy use of conventional high-pressure sodium (HPS) greenhouse lighting to that of light-emitting diode (LED) lighting. Photometric simulations of a hypothetical greenhouse were performed in three different geographic locations in the United States with widely different annual daylight availability: Albany, NY, Fairbanks, AK, and Phoenix, AZ. Simulation conditions included summer and winter, overcast and clear skies, and several lighting layouts and distributions. The analysis showed that, while maintaining the criteria levels of photosynthetic photon flux density, lighting energy savings were primarily attributable to increased LED source efficacy rather than HPS. Secondary energy savings were attributable to the ability to continuously dim LED lighting in response to daily and seasonal changes in daylight. Despite options for LED luminaires with a slim form factor, reduced crop shading compared with larger conventional HPS luminaires did not result in significant lighting energy savings.

Energy Saving Potential of Daylight Integrated Lighting System in Built-In-Environment for Various Climatic Conditions

One of the recent trends in energy efficient lighting design is integrating daylight with artificial lighting which offers a sufficient amount of energy saving. Daylight illuminance is varying with respect to time of the day as well as the time of the year. Not only that daylight is very much depended on location, calendar date, time of the day, building construction geometry, window position, etc. Thus during the design of daylight integrated lighting system the measurement of daylight availability in a space is important. In this paper, a sample open office area has mainly been considered and lighting design has been done with highly energy efficient LED light sources and potential of energy saving has been studied at various climatic conditions with different building geometry considering integration of daylight with artificial lighting system.

Comparative assessment of optical characterization of prismatic materials (PMs), using genBSDF tool for virtual simulations and a goniophotometer for physical measurements

To improve daylight availability and thermal performance of buildings, complex fenestration systems are used to redirect/distribute solar radiation indoors. We need to characterize the optical properties of these complex fenestration systems through measuring their spectral, bidirectional distribution function to evaluate their performance for energy efficiency, daylight availability, and building sustainability purposes. This paper represents the characterization of two different Prismatic Material (PM) products that apply to diverse purposes in buildings. First, we conduct two methods to measure the Bidirectional Scattering Distribution Function (BSDF) of materials; genBSDF raytracing tool of Radiance and goniophotometer measurement (goniophotometry). In the next step, we compare the genBSDF result with the results of the goniophotometry. The aim of this study is to evaluate the angular-based optical behavior of prismatic materials in distributing light and also to assess the reliability of the genBSDF tool result for further simulation of high-performance building purposes. The results demonstrate that the genBSDF raytracing tool method creates a comparable result to the goniophotometry method. Therefore, genBSDF is a robust tool for assessing the solar-optical properties of PMs.

Simulation of daylight availability, visual comfort and view clarity for a novel window system with switchable blinds in classrooms

The presence of daylight reflections on blackboards in classrooms can be disruptive to students and negatively impact their visual comfort and learning efficiency. A novel window system with switchable blinds has been specifically designed to balance daylight availability, visual comfort, and adequate window view in classrooms. This study aims to develop a validated simulation method to assess the daylighting performance of the novel window system in these three domains. Radiance-based simulation using bidirectional scattering distribution function (BSDF) data was developed and validated against experimental measurements in a test room. Daylight autonomy (DA) was used as the criterion for daylight availability, while the contrast ratio on the board was used to evaluate the disturbing light reflections on it. The simulation results show that, regardless of the classroom orientation (south/east/west), the novel window system with switchable blinds can: a) successfully meet the LEED requirements for spatial daylight autonomy (sDA) > 55%; b) reduce the low-contrast areas on the blackboard by adaptively switching the blinds, and c) maintain a satisfactory openness of the window with a clear image of the exterior. The studied window system with switchable blinds can provide a sensible balance between daylight availability, visual comfort, and view. The method of rating visual comfort in classrooms using contrast ratio on the blackboard was demonstrated to be feasible and applicable.

Visual Comfort Assessment of Hospital Patient Rooms with Climate Responsive Facades

As advanced technologies become prevalent, they are being used more widely in numerous fields. The building sector is not an exception. One of these cutting-edge technologies is responsive facades, which are used in buildings and have an undeniable effect on daylighting. However, they have not been adequately evaluated for improving visual comfort in hospitals. This study investigates visual comfort in a standard patient room, based on applying four responsive facades. Simulations were conducted using HoneybeePlus, a plugin in the Grasshopper. Simulation-based results of annual indicators, including Annual Sunlight Exposure (ASE) and spatial Daylight Autonomy (sDA), showed that different facades could result in several optimal modes. Furthermore, a more comprehensive investigation should consider factors such as Daylight Glare Probability (DGP) and Daylight Glare Index (DGI). Glare indicators revealed that facade directly affects patient visual comfort and can even have an adverse effect. When the optimal responsive facade is chosen, it enhances users' visual comfort throughout the year, yet there will be still glare probability in some cases. Based on the results, this probability decreases as patient distance increases, and Window to Wall Ratio (WWR) is not particularly effective in reducing glare. Nevertheless, when it comes to daylight availability, WWR cannot be ignored, and the first façade with WWR 60% showed the best overall performance.

DAYLIGHTING PERFORMANCE OF HIGH SCHOOL LEARNING ENVIRONMENT IN TROPICS

ABSTRACT The quality of the indoor environment, including the lighting conditions, is crucial in classrooms as it directly affects students’ learning performance and productivity. Natural light is the best light source for visual comfort, aesthetics, and energy efficiency. Malaysia is in a tropical region and has abundant daylight availability that could meet the required lighting during the day. However, in Malaysian schools, electric lights are frequently switched on during classes in the daytime; hence, daylighting is not efficiently utilised. This study investigates the daylighting performance in classrooms in a national high school in Penang, Malaysia. Fieldwork was conducted by measuring incident illumination levels inside selected classrooms in the Teluk Kumbar High School. The results show that average illumination levels were between 400 lux to 1000 lux, more than enough in most classrooms because of the relatively large windows with clear glass. The average daylight ratios recorded in the classrooms were between 6.4 and 9.2%, which may result in glare problems. Simulations were conducted using Design-Builder to further evaluate the annual daylighting performance including Daylight Autonomy (DA), Annual Sun Exposure (ASE) and Useful Daylight Illuminance (UDI). Based on the findings, it is recommended to use shading devices or replace the glazing type to improve daylighting performance for visual comfort. Proper design and selection of windows in schools can significantly improve indoor lighting quality for students and reduce solar heat gain.

A Study on Daylight Performance Evaluation in Primary School Classrooms

From the early beginning of construction in history, priority of using daylight has played an active role in the settlement decision, building shape and façade design. Today, the necessity of conscious consumption has become an accepted fact due to the depletion of energy resources. For this reason, the effective use of daylight and reducing lighting energy consumption have become one of the most important goals of today's architecture. &#x0D; The purpose of the natural lighting system is providing sufficient daylight to the target area, considering the visual comfort conditions. Nowadays, for the architectural design of buildings, the use of passive systems is primarily preferred in terms of energy efficiency. The use of natural lighting as a passive system, minimizing building lighting energy requirements and creating the desired visual environment should be prioritized in terms of providing visual comfort. In educational buildings, it is vital to design a lighting system in which daylight is used effectively in order to meet the visual needs of the instructors and students and to minimize the usage of lighting energy. Within the scope of the TS EN 17037 standard, which was developed for daylight assessment in buildings and approved by CEN on 29.07.2018 and lastly updated on 02.03.2022, the criteria for daylight assessment is handled under 4 headings: daylight provision, view out, exposure to sunlight and protection from glare. For each criteria specified in indoor daylight assessment, three grades are defined as 'minimum, medium and high'.&#x0D; In this study, the criterion of providing daylight in educational buildings was examined in accordance with the TS EN 17037 standard. With the study, it is aimed to develop an approach to determine the optimum values ​​of the parameters of direction, obstacle presence and transparency ratio in the context of providing sufficient daylight in the primary classroom design. Investigated building type is the primary school building classroom, which was created in optimum dimensions according to the characteristics of primary education classrooms defined in the ‘Educational Buildings Minimum Design Standards Guide’ published by the Ministry of National Education. It is aimed to evaluate and develop the criteria given in the ‘Educational Buildings Minimum Design Standards Guide’ according to the TS EN 17037 standard, which defines daylight performance in Turkey. The classroom model discussed within the scope of the study has been modeled with the Rhino program according to the alternative transparency rates and obstacle situations; In the simulation, the Climate Studio plugin, which was developed for the calculation of dynamic evaluation parameters, was used. The area handled by using evaluation methods according to the 17037 standard included in the software was evaluated in terms of annual daylight performance. The availability of target illuminance levels in half of the daylight hours throughout the year was calculated using the daylight autonomy method, and the climatic data of the province of Istanbul were used as a representative in the calculations. The results obtained were evaluated according to the TS EN 17037 Daylight Standard, and the scenarios created were classified as 'minimum, medium and high' according to the availability of daylight. According to this classification, optimum transparency ratio, window direction and obstacle conditions conditions for the city of Istanbul in primary school classroom design are discussed. The optimal transparency ratios for each aspect are discussed. The minimum transparency ratio values ​​given in the ‘Educational Buildings Minimum Design Standards Guide’ were compared with the optimum transparency ratios obtained.&#x0D; &#x0D; &#x0D; Keywords: Daylight Performance, TS EN 17037, Primary school classrooms, Window Design