Access To Daylight Research Articles

Enhancing daylighting predictions in urban planning: A workflow for setting bespoke Vertical Sky Component (VSC) targets

In Sweden, urban planners are legally obligated to design neighbourhoods that allow future buildings to meet daylight requirements. However, this is challenging because planners can only define the building masses, without control over future building details such as glazing ratios, room layouts, and orientation.The Vertical Sky Component (VSC) is a well-established indicator for early daylight assessments of buildings, and it is often used by Swedish urban planners to verify daylight access for their massing designs, even though it has its limitations. A VSC target value VSC ≥ 27 % has been widely applied in the urban planning practice. However, a single universal VSC target does not necessarily guarantee compliance with daylight requirements indoors. This article proposes a workflow for setting bespoke VSC targets. The goal is to provide urban planners with more reliable tools for early daylighting predictions. The workflow uses parametric simulations to establish VSC thresholds that assure compliance with current daylight regulations, such as the Swedish building code (BBR) and the European standard (EN 17037). While this article focuses on Sweden, the workflow could be readily applied to any location with prevalence of overcast sky conditions. Some potential practical urban planning applications of the workflow are suggested.

Optimizing Building Form for Daylight Access in Dense Urban Areas in the Early Stages of Design

The urgency to address climate change, the energy crisis, and indoor air quality underscores the importance of utilizing daylight as a renewable energy source in urban environments. This study delves into passive design strategies to facilitate access to sunlight and daylight within urban contexts and architectural designs, aggregating essential parameters identified in the existing literature to improve building forms for daylight accessibility. The study then develops a multi-scale, multi-objective framework integrating these passive strategies to optimize building performance in densely populated areas. Suitable approaches for incorporating daylighting at both building and urban scales are identified by examining existing passive form-finding strategies and rules of thumb. Given the implications for dense urban areas, floor area is used as an evaluation criterion, with energy use intensity (EUI) and carbon footprint serving as additional criteria in the optimization process through manual analyses and computer-based tools. By adopting a workflow that considers multiple objectives and parameters, this study aims to guide designers in integrating optimal daylighting strategies during the initial design phases.

Biophilic analogous patterns for light-responsive architecture during polar night: Examining the photobiological effects of electrical lighting on surface colour configuration

This paper investigates occupants' photobiological responses of biophilic analogous patterns such as electrical lighting and surface colour configuration during dark periods in northern architecture. Biophilic design establishes that the integration of nature-inspired architectural strategies could positively impact occupants’ photobiological responses to enhance well-being in locations with limited daylight access. Photobiological responses are indicated on image-forming (IF) and non-image forming (NIF) effects. IF relates to visual outcomes, reflected on vision and visual tasks, and measured in photopic units. NIF relates to non-visual outcomes such as the biological process of circadian clock stimulation and measured in melanopic units. Limited research addresses the impact of electrical lighting combined with surface colour (SC) configurations to optimize minimum lighting requirements at photopic and melanopic levels in an architectural setting. This research therefore examines eight surface colour configurations tested under three different luminaire positions set at warm, warm-white, and white correlated colour temperature (CCT). The variables generated 72 scenarios, which were captured through high dynamic range images (HDRi), analyzed, and post-processed to display false colour maps and values of illuminance, melanopic-Equivalent Daylight Illuminance (melanopic-EDI) and spatial colour temperature. Results demonstrate the spatial diversification generated by electrical lighting to different visual tasks and circadian stimulation over a day. The study also proved that several coloured surfaces and luminaire settings can generate similar photopic and melanopic lighting conditions despite their perceived spatial colour temperature. This research highlights the photobiological adjustment of biophilic coloured lighting ambiances provided by electrical systems in northern latitudes compromised by extreme photoperiod.

Integrative Lighting Aimed at Patients with Psychiatric and Neurological Disorders.

The purpose of this paper is to investigate the impact of circadian lighting-induced melatonin suppression on patients with psychiatric and neurological disorders in hospital wards by using an ad-hoc metrology framework and the subsequent metrics formalized by the CIE in 2018. A measurement scheme was conducted in hospital ward rooms in the Department of Neurology, Zealand University Hospital, at Roskilde in Denmark, to evaluate the photometric and colorimetric characteristics of the lighting system, as well as its influence on the circadian rhythm of the occupants. The measurement scheme included point measurements and data logging, using a spectrophotometer mounted on a tripod with adjustable height to assess the newly installed circadian lighting system. The measured spectra were uploaded to the Luox platform to calculate illuminance, CCT, MEDI, etc., in accordance with the CIE S026 standard. Furthermore, the MLIT based on MEDI data logging results was calculated. In addition to CIE S026, we have investigated the usefulness of melatonin suppression models for the assessment of circadian performance regarding measured light. From the results, the lighting conditions in the patient room for both minimal and abundant daylight access were evaluated and compared; we found that access to daylight is essential for both illumination and circadian entrainment. It can be concluded that the measurement scheme, together with the use of the Luox platform and Canva template, is suitable for the accurate and satisfactory measurement of integrative lighting that aligns with CIE requirements and recommendations.

Veggies and PV: Optimization of Building-Integrated Agriculture in an Energy Hub

Building-integrated Agriculture (BIA) is the concept of utilizing façade surfaces for crop production. The potential is to reduce land-use and to increase the utility of built-up area. If outdoor building surfaces were to be used for farming, it results in a competition for sunlight between crops, solar renewable energy (such as photovoltaics, PV), and daylight access to illuminate indoor spaces. We therefore propose a coupled BIA and multi-energy systems model that can represent various energy sources (such as sunlight) and their conversion and storage (such as façade based crop production, PV, or electric batteries) in order to optimally meet demands for building energy and food. It is formulated as a mixed integer linear program (MILP) optimization model that describes the energy flows as an annual hourly time series. The model conducts a bi-objective minimization of monetary cost and carbon emissions, resulting in a Pareto front of optimal solutions. The model meets building energy demands for cooling, heating and electricity by an optimized energy technology portfolio, as well as nutritional demands for leafy vegetables of all occupants by either BIA or supermarket purchases. We apply our model to a residential case study in Singapore, which serves as an example for a high density city with already numerous community-driven and practiced BIA initiatives ongoing. Our results show that when minimizing cost, utilizing PV is more cost efficient on highly exposed surfaces such as the roof than BIA. However, for more shaded façade surfaces, crop production can be a cost and environmentally efficient addition to building design, as the annual vegetables demand of all occupants can be covered entirely by self-grown produce.

Input data requirements for daylight simulations in urban densifications

One of the biggest challenges in urban densifications is securing adequate daylight access. This study examines the potential of using semantic 3D city models as input to daylight simulations. It is focusing on investigating input data requirements to these simulations from a geodata, 3D city model specification and measuring guideline perspective. To achieve this, geodata simulation input requirements for the most common daylight metrics are documented. Next, 3D city model data from two Swedish municipalities along with 3D data constructed by ourselves in CAD- and GIS-environments are utilized to explore the impact of using 3D city models of different levels of detail (LOD) and positional accuracy in daylight simulations linked to Swedish and European laws and recommendations. Similarly, the measuring guidelines and 3D city model specification requirements related to balconies and other façade accessories are also evaluated along with the utilization of façade reflectance properties and colour. It is found that LOD1 is sufficient for the obstruction angle metric for most roof types but for e.g., gabled roofs LOD2 should be used. A positional accuracy on a decimetre-level is accurate enough for the aforementioned metric. Daylight factor simulations require that balconies and façade accessories protruding more than a couple of decimetres must be represented in the 3D city model along with information on façade material and colour. The outcome of the study is expressed in the form of a list of recommendations for the creation of national profiles of 3D city models supporting daylight simulations.

Non-visual daylight potential in offices: a parametric study

A building design where appropriate daylighting is considered from early stages can enhance the building’s energy performance, as well as human well-being and productivity. Daylight naturally regulates our daily biological clock, which synchronizes our circadian rhythms. This paper presents a simulation-based parametric study to evaluate the non-visual daylight potential. A side-lit single office room in the Danish climate was simulated in Grasshopper 3D. Using the Lark plug-in, grid-based and image-based workflows were created to generate illuminance, circadian light and Equivalent Melanopic Lux. In this study we compared two design cases with extremely high and low thermal and daylighting conditions. The impact of orientation on the circadian rhythms of a sitting person with a pre-defined view-direction under an overcast and a clear sky was investigated. The results indicate that certain design combinations can minimize daylight access up to three times leading to a higher risk of circadian disruption. These disruptions were the highest in winter and under the overcast sky. No clear impact of the building-orientation on the circadian stimulation for the defined view-direction was observed. Hence, it is essential that the view-direction is set optimally. Evaluating circadian response in early phases can lead to inclusive decision-making for enhanced indoor conditions.

Users’ window preferences and motivations of shading control: Influence of cultural characteristics

Window shading control is motivated by many reasons. Very few studies consider the influence of non-physical factors that underpin occupant motives for shading control. A candidate reason that concerned this study was cultural differences. Diverging values, beliefs and norms can lead to different design considerations for building architecture to accommodate users’ expectations. This can also influence a wider array of window functions, e.g., daylight access, thermal comfort, natural ventilation, privacy and view out. We investigated the influence of cultural differences in this context. An online survey was administered to collect responses from Arab and non-Arab population groups from across the globe. We compared how occupants would prioritise different window functions in their typical workspaces to better meet their needs across these two groups. The analyses showed that Arab respondents prioritised privacy more than non-Arab respondents. The importance placed on privacy was consistently larger for the Arab group when they worked from their own residential home (r = −0.36), rather than at their office workspace (r = −0.16). Shading control for daylight access was a highly prioritised motive for both groups, which was also equally weighted as the most important reason for both opening and closing window shades with no statistical difference (r = -0.10) found between both groups. Thermal comfort was deemed more important by the Arab respondents, although this may have been caused by climate factors. The study highlights how culture has important implications on window preferences and shading control, which can be influential in the context of design considerations to accommodate user needs.

Efficacy of Korea’s Diagonal Plane Restriction for Daylight: Focusing on South-North Direction Blocks within Seoul’s General Residential Districts

Since the beginning of the 20th century, daylight access-related regulations have been an integral part of urban development. The Diagonal Plane Restriction in South Korea is one such regulation. This paper evaluates the effectiveness of the policy by investigating buildings in General Residential Districts in Seoul and the factors that have influenced its success. First, selected buildings were analyzed based on their relative core locations, massing morphology, and the glazing proportions on the south elevations. The initial results showed that nearly 50% of the selected buildings had cores on the south side, thus limiting daylight infiltration to the habitable spaces with a glazing ratio under 30%. Secondly, binary logistic regression was performed between identified types and variables to identify the primary factors affecting the ineffective arrangement. The year of a building’s construction and its primary use can significantly predict the effective applicability of a restriction. Lastly, further descriptive analysis shows how policy changes directly contributed to the growth of low-performing types and commercial uses in residential districts. The results of this study point to the shortcomings of urban policy-making without considering the particulars of each urban context. Our findings could assist planners and policy-makers in redesigning regulations for ensuring optimal daylight access in residential districts.

Energy Savings of an Optimized Daylight-Pipe System With Single and Dual Reflectors in Tropical Climates of India

Abstract Buildings in India consume over one-third of the country’s total electricity consumption and out of which about 28% and 25% are accounted for lighting energy in the residential and commercial buildings, respectively. Passive daylighting system using tubular daylight-pipe is a promising technique to save lighting energy by illuminating deep building interiors that have no daylight access through exterior windows. In this study, an innovative daylight-pipe has been designed and developed for enhanced daylighting performance by optimizing configurations of single and dual reflectors at its receiver. A detailed daylight assessment has been carried out using controlled experimentation while varying the reflectors position and orientation inside the hemispherical receiver of the daylight-pipe. It has been found that the single reflector oriented toward south has the best performance with a light transmission efficiency of 35.6%. Furthermore, monthly electrical energy savings due to the advanced daylight-pipe along with various supplementary electrical lighting options such as incandescent bulb, compact fluorescent lamp (CFL), and light emitting diode (LED) were estimated and compared for various climatic locations of India. From these evaluations, a lighting energy saving up to 23% has been observed in the summer month of May for temperate climate of Pune and hot-dry climate of Jodhpur.

External shading form-finding: simulating daylighting and dynamic view access assessment

Providing sufficient daylight and view access to the outdoors is crucial to creating a productive work environment and ensuring employees’ wellbeing and mental health in offices. To these aims, determining an optimum shading form can be challenging for designers. This study applied an ‘external shading form-finding’ and a novel ‘dynamic view access assessment’ method to find the optimum shading devices from 723 shading systems. Each system contains a typical louvre blade with two equidistant shading devices. These were externally fixed in front of a south-facing window with a dynamic interior blind, and were tested across three window-to-wall ratios. Optimum forms were selected according to LEED v4 daylight needs and unobstructed views. The results indicate that these proposed methods have the potential to support decision-making related to shading design, helping designers and architects to study the view quantitatively and combine its results with daylight assessment leading to improved building performance, employee mental health and wellbeing.

Adaptable modular construction systems and multi-objective optimisation strategies for mass-customised housing: A new user-driven paradigm for high-rise living in Hong Kong

There has been a recent increase in the exploration of ‘the discrete’ in architecture, speculating on how an integrated approach to design, fabrication, assembly and inhabitation can disrupt the traditional investment- and decision-making models in the housing industry. Strategically designed part-to-whole systems allow for differentiation and reconfiguration, and the incorporation of different end-user’ requirements. This potential of ‘democratising’ housing production requires further research into how the negotiation between multiple stakeholders’ preferences can be guided through digital methods. This paper presents a research-by-design project that applies a digital and discrete material system to high-rise housing in Hong Kong, a typology which often features high degrees of standardisation. Through the development of an adaptable modular construction system and a multi-objective optimisation workflow, a system is explored that addresses the challenges of high-rise construction, and of customising high-density housing. The case study project demonstrates the ability of the workflow’s evolutionary algorithm to balance complex requirements including maximising views, daylight access and internal connectivity according to diverse user requirements.

Lighting conditions in physiotherapy centres: A comparative field study

Visual comfort plays a central role in building occupants’ comfort, well-being and productivity. It is therefore fundamental to meet the occupants’ visual and lighting needs, carefully accounting for the room layout, usage and activities. In this framework, physiotherapy centres constitute a peculiar case since they are occupied by therapists and patients from different age groups, engaged in various activities performed in different positions in the rooms, and affected by different health issues. Lighting quality and satisfaction were monitored in four physiotherapy centres in Northern Italy and Denmark. Subjective assessments were compared with objective illuminance measurements at the task areas, and the sites were also analysed in terms of window and architectural features. Moreover, the interaction between visual and other environmental perceptions was studied. The results revealed: (1) positive influence of daylight access on the satisfaction of occupants; (2) occupants’ complaints about low lighting levels associated with artificial lighting being unable to provide 300 lx and natural light not balancing this lack of illumination; and (3) lower satisfaction among therapists, who also showed the tendency to assess their environmental perception more globally, since correlations between light and daylight satisfaction and other stimuli were observed when comfort issues were present.

Dense and Proximate Development—Daylight in the Downtown Area of a Compact City

Daylight is of utmost importance and should be the main source of light in most areas dedicated to working and living. When considering our contemporary way of living, it can be easily discerned that most of our life is spent indoors, yet in a typical architectonic design approach, daylight is too often hardly of consequence. Hence daylight becomes a critical factor. Designers comply with the legal requirements of the solar hours required for areas subjected to constant use. Simultaneously for electrical engineers’ daylight is only an additional source of light valued only where energy efficiency is concerned. The basic idea of this research is to, starting from the concept level, design the building’s volume in line with energy efficiency requirements and user expectations using daylight access strategy as the main parameter. This scope of research has been a subject of various scientific theses conducted within the last years at the Faculty of Architecture Warsaw University of Technology. This paper is dedicated to the latest and most developed outcomes. The presented solution is an architectonic point of view dedicated to the use of the daylight factor in office areas located in a dense city district that may support efficient energy requirements, including the requirements of the electric lighting system. Illumination values were set according to the BREEAM daylight and PN-EN 17037 Daylight of Buildings standard. The presented strategy is unconventional for Poland, but has the potential to be included in practice and should be developed further, together with electrical engineers, as a part of energy-saving solutions. Possibly, it should be followed simultaneously with the development of the compact cities ideas. It is hoped that it might be a starting point for discussion, and for a more detailed interdisciplinary research in the future.

The NEXT.ROOM: Design principles and systems trials of a novel test room aimed at deepening our knowledge on human comfort

Occupants' interaction with building systems, and more generally occupants’ behaviour, is strongly related to human perception of the surroundings. Progresses in human comfort theories rely upon data collection during tailored experiments, stressing the influence of single or specific combinations of environmental stimuli on diversified human responses. Laboratory experiments are typically performed in test rooms, i.e., rooms that are equipped to provide continuously monitored and controlled environmental boundaries. The NEXT.ROOM is a novel test room built up for investigating the multidisciplinary complexity of human perception, by controlling and monitoring environmental factors belonging to the four domains of comfort (thermal, visual, air quality, and acoustics) through centralized and human-centred systems. The study presents rationales behind its design and the selection of human-centred dedicated devices. Trials of the installed systems provide operational ranges for designing human comfort experiments to be performed within the NEXT.ROOM. Limits in fast-dynamics and range of internal temperature are also highlighted, since the adopted systems are mainly associated to common residential uses. The internal position of the test room also limits daylight access but the window designed in-line with the external laboratory window still guarantees the outdoor view from inside the NEXT.ROOM. A further innovation is the introduction of Virtual Reality tools for testing different internal layouts or even outdoor scenarios under highly controlled and carefully monitored environmental conditions.

Evaluation of visual and non-visual effects of daylighting in healthcare patient rooms using climate-based daylight metrics and melanopic metrics

Daylight access in healthcare facilities is essential for creating comfortable ambiance conditions for the patients during their accommodation in a hospital. The aim of this paper is to investigate how the window size, the location (Paralimni in Cyprus and Brussels in Belgium), the room orientation and patients’ gaze direction have an impact on visual and non-visual effects. This research focuses on hospitals’ most typical patient room: the double room (3.50m * 5.50m). The building parameters under study arc eight orientations and three window sizes. Moreover, other parameters are the timing (season and hour in a day), the patient placement inside the room, and the patient gaze directions. For this study, computer simulations are used for daylight assessment using climatc-bascd daylight metrics and CIE S026 melanopic metrics for non-visual effects. Research findings show that it is possible to examine design options through a comprehensive investigation of climatc-bascd daylight metrics and CIE S 026 melanopic metrics for optimised performance for visual and non-visual effects.

Time-based restriction and refeeding programmes in growing rabbits: Effects on feeding behaviour, feed efficiency, nutrient digestibility, and caecal fermentative activity

The present study evaluated the effect of five feeding programmes (AL, ad libitum feeding; DF, daylight access to feed followed by fast full refeeding; NF, nightly access to feed and fast full refeeding; NS, nightly access to feed and slow full refeeding; NI, night access to feed until the end of the trial) on growth, nutrient digestibility, caecal fermentative activity, and carcass and meat quality of 400 crossbred rabbits housed in 40 open-top pens (10 rabbits/pen) from weaning to slaughter (28–70 days of age). In all feed-restricted rabbits, feeding time decreased from 14 to 9 h/day during the 1st week, it stood at 8 h/day during the 2nd week, and it increased from the beginning of the 3rd week according to three refeeding systems: i) fast until ad libitum (+4 h/day until 24 h/day) for the DF and NF groups; ii) slow until ad libitum (+1 h/day until 24 h/day) for the NS group; and iii) very slow and until 12-h-restriction (+30 min/day until 12 h/day) for the NI group. During the restriction period, DF and NF programmes compared with the AL programme, improved the coefficient of total tract apparent digestibility (CTTAD) for crude protein (+4.6%) and ether extract (+2.7%) (P < 0.001); NF programmes increased caecal volatile fatty acids (VFA) (79.7 vs 67.7 mmol/L; P = 0.034) and decreased pH (5.32 vs 5.46; P = 0.013) compared with AL. During the refeeding period, the NI programme increased the CTTAD of dry matter (+2.9%; P = 0.001), crude protein (+3.9%; P = 0.003), and gross energy (+2.6%; P = 0.001) compared with the DF and NF groups. The AL, DF, and NF treatments decreased caecal VFA compared with NS and NI (81.0 mmol/L vs. 95.4 mmol/L; P < 0.001). In the whole trial, the NI programme decreased feed intake (−7.5%; P < 0.001) and feed conversion (−6.7%; P = 0.002) compared with the AL programme, without differences in growth, final live weight, and slaughter traits among groups. Compared to AL feeding, feed restriction increased the mortality rate due to digestive disorders (9.0 vs 1.6%; P = 0.036), without affecting morbidity and health risk index. Slaughter weight (on average: 2608 g), carcass yield (60.2 g/100 g live weight at slaughter), and carcass and meat quality traits were not affected. In conclusion, the NI programme improved feed efficiency without impairing growth, slaughter, and carcass traits.

THE EFFECT OF OPENING DISTRIBUTION AREA MODIFICATION ON HORIZONTAL LIGHT PIPE DAYLIGHT PERFORMANCE

A deep-plan office building design limits daylight access on the workspace distant from the side window. Horizontal Light Pipe (HLP) is one of the light transport systems that can deliver daylight to these areas. The research aim was to explain and evaluate the effect of HLP’s opening distribution area on daylight performance at deep plan-private office space. The research method was experimental with simulation as a tool. Daylight level and distribution of the base case, HLP with an opening distribution area of 6.6 m2 were compared with the case, HLP with an opening distribution area of 3.41 m2. The results showed that both cases distributed daylight uniformly. A 50% reduction of HLP’s opening distribution area, from 6.6 m2 to 3.41 m2 improved the average Daylight Factor as big as 6.42%. HLP with a smaller opening distribution area can be applied as the main source of daylight on deep-plan office spaces

A data-driven method to minimize sensor use for dynamic shading control

Dynamic facade systems are a promising strategy to balance the benefits and drawbacks of daylight penetration through the window in a built environment. A well-operated shading system should allow for sufficient daylight access while preventing glare in response to changing weather conditions. The dynamic shading system can also help with making use of daylight to reduce the lighting energy use when integrated with electric lighting control. This paper presented a data-driven approach to control the automated shading system. The control method allows the system to be responsive to outdoor weather conditions. With data from offline daylight simulation using typical meteorological year weather, three machine learning classification algorithms were applied to train predictive models for online shading control. The proposed method was validated using a climate-based simulation. It was found that all models had a satisfying prediction performance, with an accuracy of 0.85 to 0.92. The shading control could maintain the work plane illuminance for 97% to 99% of the time during the year. It was also associated with a potential of reducing electric lighting energy use by 40% to 43% compared to that of on/off lighting control.

The impact of regulations on the typo-morphological transformation of residential buildings in Tehran

The typo-morphology of residential buildings in Tehran has changed tremendously from the introduction of the first building and urban regulations in the 1950s. This paper explores the role of these regulations in typo-morphological changes, how the internal arrangement and building form of residential architecture were shaped, and the nature and extent of how the layouts were influenced by building and urban regulations. A morphological and typological analysis of residential buildings was carried out and validated by in-depth interviews. The regulations with the greatest effect on typo-morphological changes include the land subdivision system, the occupancy level code, parking regulations, staircase and elevator requirements and daylight access such as patio spaces. This research also identifies issues for policy-makers to consider in any review of the building and urban regulations and their enforcement in the design process.