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At the conceptual-stage, building performance simulation (BPS) based evaluations are being increasingly used for tasks such as ranking of competing massing design proposals. However, such conceptual stage evaluations suffer from information deficiency in building level design attributes. The resulting uncertainty in performance evaluations raises questions regarding their usefulness for decision-making. We used a risk-based decision evaluation metric called expected opportunity loss to assess the reliability of a BPS-based ranking of conceptual stage massing schemes. We found daylighting assessments (spatial Daylight Autonomy) to be least reliable, with 22% chance of making an incorrect decision at the conceptual stage, followed by annual heating (15%) and cooling demand (8%). This work provides a structured framework for evaluating utility of conceptual stage BPS models and a purposeful basis for integration of BPS assessments in the design process, subject to level of design development. [ABSTRACT FROM AUTHOR]

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically used. However, as our IIL responses depend on the spectral characteristics of light, spectral simulations are required. The goal of this study is to validate two spectral simulation tools, ALFA and Lark, for the study of indoor spaces in relation to occupants' IIL responses. Indicators associated with IIL responses derived from ALFA- and Lark-simulated data are compared against indicators derived from data measured under indoor daylighting and electric lighting conditions. The results show that Lark outperforms ALFA in most cases, with a simulation error in the ±20% range for point-in-time indicators. When accounting for time dynamics of light exposure, at least 9% of the daylight exposures simulated for a 6-h period in Lark lead to a significant error. [ABSTRACT FROM AUTHOR]

Window views that provide visual connections to the outdoors have been shown to have multiple positive effects on occupants (Heschong [25]). Definition Design teams regularly analyze building performance, including energy and indoor environmental quality to support the building design, starting with conceptual design and continuing throughout the complete design process. In contrast, at later design stages, it is possible to consider more specific variables regarding facade materials, building program, and occupant characteristics using complex metrics such as spatial and temporal analyses. The first approach is binary (informing the design team "what to do, and what not to do"), while the second approach is a sensitivity issue to improve the building design, construction, retrofitting, maintenance, or operational change, and provide "better than just enough.". [Extracted from the article]

The size of window openings is widely acknowledged as an important factor in our spatial perception. However, little is known about how the perception and preference of windows changes between countries, leaving a gap of knowledge regarding the applicability of research findings across latitudes. This article presents the outcomes of a study investigating regional differences in the perception of spaces with varying window size (small, medium, and large), space size (small and large), spatial context (working and social), and sky type (overcast and two types of clear sky). As the regional differences were the main studied factor, the study was performed in Norway, Switzerland, and Greece, representing northern, central, and southern European latitudes, respectively, and used virtual reality as a means to replicate the same experiment in different locations. In total, 406 participants evaluated eight spatial attributes using an 11-point Likert-type scale. Results indicated that regional differences could be observed in the participants' responses, with significant differences in how pleasant and calm the space was perceived, found not only between participants in Greece and Norway in all the studied window sizes, but also between Greece and Switzerland for the medium and large windows, indicating that even small variations in latitude within Europe can affect the spatial perception. The findings of this study reveal that spaces with specific fenestration characteristics might not induce the same response across different latitudes in Europe, and thus, have important implications for daylighting and architectural design, which would motivate the use of region-specific parameters. [ABSTRACT FROM AUTHOR]

Building Performance Simulation (BPS), a useful tool to assess the operational performance of buildings and systems, can often be computationally expensive. The use of BPS is cumbersome for problems where the speed of response is important, e.g. real-time control, uncertainty quantification, parametric exploration, or stock modelling. Emulators, such as those based on regression, offer a faster substitute, but their reliability can be questionable. This paper proposes seven tests to check if an emulator is a suitable replacement for simulation in practice. The tests are categorized using four criteria: accuracy, speed, generalisability, and ease of use. The tests can be included in the process of setting up an emulator-based workflow. A use case is provided for emulators based on linear and non-linear regression (Gaussian Process models). This work aims to enable a practitioner to reliably conduct performance assessment for buildings using emulators. [ABSTRACT FROM AUTHOR]

Daylight provision to the indoor space is affected by different building elements that cannot be fully controlled by the users, such as the window size of a space. The dimensions of the fenestration not only affect the lighting levels, but they also affect how the space is perceived by its users. The present study examines three different window sizes via virtual reality, to study how they affect the perception of both a small and a large space at high latitudes. Additionally, two context scenarios (socializing and working), as well as three different sky types (overcast sky and clear skies with either high or low sun angle) were evaluated. The experimental study applied a mixed design with within-subjects and between-subjects factors. A total of 150 participants evaluated the scenes using a Likert-type scale to rate eight different subjective attributes. The statistical results showed that both window size and space type significantly affect the participants' spatial perception, as well as their satisfaction with the amount of outside view. Larger windows led to more positively evaluated spaces for all studied attributes. Moreover, a significant interaction was found between window size and type of space for the satisfaction with the amount of view in the space, indicating that the window size was dependent on the type of space in which the windows are located. Specifically, the window sizes were rated higher in the small space than in the large space for the evaluation of amount of view. The findings show that window size affects how people perceive a space, and additionally, that other spatial features, such as space type, affect window size preferences. [ABSTRACT FROM AUTHOR]

This paper presents the combined effect of indoor temperature (19 °C, 22 °C, and 26 °C) and colored glazing (blue, orange, and neutral) on visual perception of daylight. Experiments were performed in an office-like test room, in which 75 participants were fully immersed under visual and thermal stimuli. Findings are discussed in terms of cross-modal effects of indoor temperature on visual perception, as well as of unimodal effects of glazing color on visual perception, investigated in terms of color of light and visual environment evaluations. Results show the presence of cross-modal effects of indoor temperature on visual perception of both the visual environment and the color of light. Indoor temperature affected the visual environment evaluation as, first, brightness comfort resulted higher at lower temperatures, and second, the light was associated to warmth adjectives more often at higher temperatures. On the other hand, indoor temperature influenced the color of light evaluation as, only at lower temperatures, daylight tinted by the blue glazing was considered less pleasant and less comfortable, and was chosen less often over the daylight tinted by the orange glazing. In terms of unimodal effect of colored glazing on visual perception, results indicate that the neutral glazing was always preferred over the two colored ones, probably due to the use of saturated colors. The orange glazing, however, was associated with the most relaxing and warmest daylight. These findings have important implications regarding the use of glazing with saturated colors in buildings and expand our understanding of temperature–color interaction – so far investigated only with electric light – to daylight evaluations. [ABSTRACT FROM AUTHOR]

Façade design is claimed to fulfil a number of requirements in workplaces, ranging from privacy to safety and from comfort to aesthetics. For future R&D efforts in façade design, identifying the key drivers that should shape contemporary facades in office buildings is not always an easy task because of the discrepancies that can emerge between the diverse expectations from professionals and the possible conflicts that can exist in conciliating global design trends with local climate constraints. This research aims to enrich the debate on façade design developments for office buildings, by discussing the outcomes of an on-line survey distributed worldwide among professionals working in the building design sector. Outcomes of 245 responses are summarized in an interactive chart that enables to visualize the potential of some main aspects and technologies characterizing today's office building skins. The potential is shown based on the observed level of relevance among different professional profiles or climates. While energy and comfort emerged as the aspects attaining global and interdisciplinary consensus, the features that entailed psychological or emotional reactions attracted the most diverse evaluations. Despite not being fully exhaustive, the observations arising from this study can help with identifying possible research and developments gaps in the field. [ABSTRACT FROM AUTHOR]

This article presents a novel experimental method that uses a virtual reality (VR) headset, aiming to provide an alternative environment for the conduction of subjective assessments of daylit spaces. This method can overcome the difficulty of controlling the variation of luminous conditions, one of the main challenges in experimental studies using daylight, and its novelty lies in the implementation of physically based renderings into an immersive virtual environment. The present work investigates the adequacy of the proposed method to evaluate five aspects of subjective perception of daylit spaces: the perceived pleasantness, interest, excitement, complexity, and satisfaction with the amount of view in the space. To this end, experiments with 29 participants were conducted to compare users' perceptions of a real daylit environment and its equivalent representation in VR and test the effect of the display method on the participants' perceptual evaluations, reported physical symptoms, and perceived presence in the virtual space. The results indicate a high level of perceptual accuracy, showing no significant differences between the real and virtual environments on the studied evaluations. In addition, there was a high level of perceived presence in the virtual environment and no significant effects on the participants' physical symptoms after the use of the VR headset. Following these findings, the presented experimental method in VR seems very promising for use as a surrogate to real environments in investigating the aforementioned five dimensions of perception in daylit spaces. [ABSTRACT FROM AUTHOR]

Previous studies have shown that the choice of the behavioural model for the control of lighting and shading devices has important implications in the energy performance assessment of office buildings and directly influences the comparison of design alternatives for control systems as well as for the façades (shading or glazing). Since many behavioural models exist for the same purposes, and in most cases there is no consensus on which ones are more representative of the reality, it is important to perform more real-world observations and draw lessons from them. This study appears in this context and explores the results of a field campaign that continuously monitored occupants’ behaviour regarding manual control of electric lighting and shading devices of eight real-world single offices under normal operation. Detailed measurements and observations were performed over two months in each office with the aim of assessing the level of agreement between existing behavioural models and actual occupants’ behaviour. Findings from this study enabled refining the hypothesis regarding realistic modelling of occupants’ behaviour when considering currently available whole building simulation (BS) software; moreover, needed improvements to increase the reliability of the results in whole BS were identified. [ABSTRACT FROM PUBLISHER]

Successful daylighting design is a complex task which requires the designer to consider numerous design elements and their effects on multiple performance criteria. Facades, in particular, include many variables which may dramatically impact daylighting performance. Genetic algorithms (GAs) are optimization methods which are suitable for searching large solution spaces, such as those presented by design problems. This article presents a GA-based tool which facilitates the exploration of facade designs generated based on illuminance and/or glare objectives. The method allows the user to input an original 3d massing model and performance goals. The overall building form remains the same while facade elements may change. Ten parameters are considered, including materials and geometry of apertures and shading devices. A simple building data model is used to automatically generate a 3d model of each solution. Results from single- and multi-objective case studies are presented to demonstrate a successful goal-driven design exploration process. [ABSTRACT FROM AUTHOR]

Decisions affecting building form and orientation, and choices regarding opening size, type and positioning have a great effect on the building's access to daylight and are typically made during the earliest stages of architectural design. Computer simulations of daylight performance have become a powerful tool for making design decisions, especially since the diurnal and seasonal changes in daylight necessitate an annual, climate inclusive performance analysis because of the strong influence of climate conditions on daylight accessibility. However, the amount and complexity of information generated by an annual analysis can be overwhelming, so a need exists for appropriate, user-friendly methods to process and communicate these data to the designer. To address this problem, an alternative approach to traditional daylight analysis is explored here to develop appropriate goal-based metrics and annual graphic display formats which present illuminance, glare and solar heat gain data with a focus on time variations. Graphic outputs are created using the temporal map format to improve understanding of daylight performance as it varies over the year, and to enable comparisons to be made between spatial and non-spatial quantities. In particular, a consistent and intuitive triangular colour scale is proposed to express goal compliance, so as to enhance further comparability between dissimilar quantities and thereby assist with critical choices and performance tradeoffs during the design process. Les décisions affectant la forme et l'orientation d'un bâtiment et les choix relatifs à la taille, au type et au positionnement des ouvertures ont une grande influence sur l'accès du bâtiment à la lumière naturelle et sont habituellement opérés dans les toutes premières phases de la conception architecturale. Les simulations informatiques de la performance en éclairage naturel sont devenues un puissant outil de prise de décision en matière de conception, en particulier dans la mesure où les variations de la lumière naturelle au fil de la journée et des saisons nécessitent une analyse annuelle de la performance qui prend en compte le climat, vu sa grande influence sur l'accès à la lumière naturelle. Cependant, l'on peut être submergé par le volume et la complexité des informations générées par une telle analyse annuelle, de sorte qu' un besoin émerge pour des méthodes plus intuitives et adaptées pour traiter ces données et les communiquer au concepteur. Afin de remédier à ce problème, il est exploré une approche alternative est explorée ici, visant à développer des techniques de mesures fondées sur des objectifs, et des formats de représentation graphique annuelle présentant les données relatives à l'éclairement, à l'éblouissement et à et aux gains solaires en mettant l'accent sur les variations sur le temps. Des visualisations graphiques sont créées, qui utilisent le format des cartes temporelles pour améliorer la compréhension de la performance lumineuse naturelle selon ses variations au fil de l'année, et pour permettre d'effectuer des comparaisons entre des données spatiales et non spatiales. En particulier, une échelle de couleurs triangulaire, constante et intuitive, est proposée pour exprimer une conformité aux objectifs, de façon à renforcer une comparabilité entre des volumes de données dissemblables et aider ainsi à opérer des choix cruciaux et des compromis de performance au cours du processus de conception. performance des bâtiments éclairage naturel outils de simulation éblouissement techniques de mesures fondées sur les objectifs éclairement, gains solaires cartes temporelles [ABSTRACT FROM PUBLISHER]

Heuristics and simple design guides are important tools for designers who wish to incorporate daylighting into the early design process. This paper describes a simulation-based method for generating simple rules for facade design based on specific climate data. This approach uses a design of experiments methodology to populate a detailed daylighting knowledge base. To enable consideration of both visual performance and visual comfort, the knowledge base contains information about whole-year, climate-based illuminance and glare metrics. The design parameters considered include window and shading device geometry and glazing materials. The approach illustrates how various design elements affect daylighting performance and provides a simple way to approach daylighting early in the design process. It can be employed for design and in educational settings. [ABSTRACT FROM AUTHOR]

The effective integration of daylighting considerations into the design process requires many issues to be considered simultaneously, such as daily and seasonal variations, illumination, and thermal comfort. To address the need for early integration into the design process, a new approach called Lightsolve has been developed. Its key objectives are to support the design process using a goal-oriented approach based on iterative design improvement suggestions; to provide climate-based annual metrics in a visual and synthesized format; and to relate quantitative and qualitative performance criteria using daylighting analysis data in various forms. This methodology includes the development of a time-segmentation process to represent weather and time in a condensed form, the adaptation of daylight metrics that encompass temporal and spatial considerations, and the creation of an interactive analysis interface to explore design options and design iterations. This system relies on optimization techniques to generate these suggestions. Lightsolve allows the designer to explore other design alternatives that may better fulfil the objectives and to learn about appropriate strategies to resolve daylight or sunlight penetration issues. It offers architects and building engineers support for daylighting design that can be employed interactively within the existing design process. L'integration des aspects relatifs a l'eclairage naturel dans un projet d'architecture exige l'etude simultanee de nombreuses questions comme ses variations quotidiennes et saisonnieres ou l'equilibre entre le niveau d'eclairement et le confort thermique. Afin de repondre a la necessite d'une integration rapide dans le processus de conception architecturale, une nouvelle approche baptisee Lightsolve a ete mise au point. Ses principaux objectifs sont les suivants: guider le processus par une approche inverse s'appuyant sur des suggestions iteratives d'amelioration du projet; fournir des parametres annuels bases sur le climat sous forme visuelle et synthetique; mettre en relation les criteres de performance quantitatifs et qualitatifs en utilisant diverses formes de donnees d'analyse d'eclairage naturel. Cette methodologie inclut le developpement d'un processus de segmentation temporelle permettant de representer les conditions meteorologiques ainsi que la date ou l'heure sous forme condensee; elle permet egalement d'englober des considerations temporelles et spatiales pour l'eclairage naturel et comprend la creation d'une interface d'analyse interactive pour explorer les options et les iterations du projet dans sa phase conceptuelle. Ce systeme repose sur des techniques d'optimisation qui generent des suggestions de modifications. La methode Lightsolve permet ainsi au concepteur d'explorer d'autres alternatives pour son projet, susceptibles de mieux atteindre les objectifs vises et de s'informer sur des strategies appropriees permettant de resoudre des problemes d'eclairage naturel et de penetration de la lumiere directe du soleil. Elle offre aux architectes et aux ingenieurs en batiments une aide a la conception en eclairage naturel qui peut etre utilisee de maniere interactive, afin de ne pas perturber le processus de conception architecturale. Mots cles: eclairage natural, processus de conception architecturale, aide a la conception, energie, optimisation interactive, simulation, visualisation [ABSTRACT FROM AUTHOR]

Many conventional daylighting design tools are limited in that each simulation represents only one time of year and time of day (or a single, theoretical overcast sky condition). Since daylight is so variable -- due to the movement of the sun, changing seasons, and diverse weather conditions -- one moment is hardly representative of the overall quality of the daylighting design, which is why climate-based, dynamic performance metrics like Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI) are so needed. Going one step further, the annual variation in performance (condensed to a percentage by DA and UDI) is also valuable information, as is the ability to link this data to spatial visualizations and renderings. Trying to realize this combination of analytical needs using existing tools would become an overly time-consuming and tedious process. The challenge is to provide all information necessary to early design stage decision-making in a manageable form, while retaining the continuity of annual data. This paper introduces a climate data simplification method based on a splitting of the year into 56 periods, over which weather conditions are "averaged" and simulated using Perez's ASRC-CIE sky model, while information on sun penetration is provided at a greater resolution. The graphical output of the produced data in the form of "Temporal Maps" will be shown to be visually, and even numerically, comparable to reference case maps created using short time step calculations and based on illuminance data generated by Daysim. [ABSTRACT FROM AUTHOR]

Recent studies have attempted to link environmental cues, such as lighting, with human performance and health, and initial findings seem to indicate a positive correlation between the two. Light is the major environmental time cue that resets the human circadian pacemaker, an endogenous clock in the hypothalamus that controls the timing of many 24-hour rhythms in physiology and behavior. Insufficient or inappropriate light exposure can disrupt normal circadian rhythms which may result in adverse consequences for human performance, health and safety. This article addresses the problem of prospective analysis of building architecture for circadian stimulus potential based on the state of the art in photobiology. Three variables were considered in this analysis: lighting intensity, timing, and spectrum. Intensity is a standard design tool frequently used in illuminating engineering. Timing and spectrum are not commonplace considerations, so the analysis that follows proposes tools to quantitatively address these additional requirements. Outcomes of photobiology research were used in this paper to define threshold values for illumination in terms of spectrum, intensity, and timing of light at the human eye, and were translated into goals for simulation -- and ultimately for building design. In particular, the climate-based Daylight Autonomy (DA) metric was chosen to simulate the probabilistic and temporal potential of daylight for human health needs. The developed method was applied to study the impact of key architectural decisions on achieving prescribed stimulus of the circadian system in a hospital patient room design; studied variables included orientation, window size, and glazing material. A healthcare setting was specifically chosen with the intent of follow-on research to validate our findings with actual patient outcome data. [ABSTRACT FROM AUTHOR]

Among the three components of daylight affecting a surface's illumination inside a room, the direct component, due to light flux reaching the surface element directly from the sky, (also called sky factor) is the most significant one. Its estimation must therefore be as accurate as possible when assessing the daylighting performances of a building. To estimate its value for a given surface, analytical methods can be employed, based on the luminance distribution of the sky and the window's geometric properties: dimensions and position in regard to the surface element. However, such methods have always been restricted to vertical and horizontal windows, requiring heavy approximations to be applied whenever a tilted rectangular opening was considered. A generalized method for assessing the sky component is proposed here, extending it to rectangular windows of any tilt angle. As a purely analytical result could not be derived, it is based on an optimized combination of vertical and horizontal windows situations. To validate the methodology, scale model measurements were performed with a sky simulator for two rectangular openings of varying tilt angle (every 15° from vertical to horizontal): the experimental results proved to be in very good agreement with the calculation-based approach. [ABSTRACT FROM AUTHOR]

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