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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.

While there is a growing use of complex façade designs in contemporary architecture worldwide and across Europe, little is known about the perceptual effects of these façades and the resulting daylight patterns on occupants, or about how such effects might differ between European latitudes. This study examines the perception of façade and daylight patterns across Europe by replicating a virtual reality (VR) experiment in Norway, Switzerland and Greece, using a mixed experimental design to jointly investigate the influence of different factors on the perception of a daylit interior space. These factors included: façade geometry (within-subject factor with four contemporary façade designs of equal aperture ratio), sky type (clear sky with high or low sun angle, or overcast sky), spatial context (socializing or working), and country (Norway, Switzerland, or Greece). Results showed that, among the manipulated factors, only the façade geometry affected the studied attributes (how pleasant, interesting, exciting, calming, complex, spacious, and bright the space was perceived, and the satisfaction with the amount of view in the space). Regional effects were observed only for reported brightness, with higher evaluations from participants in Greece than in Norway, but are difficult to generalize due to limitations stemming from the use of VR and the conduction of experiments in different seasons (summer and early fall) in the two countries. These findings show that façade design is a crucial feature in our spatial experience, inducing equivalent perceptual effects, such as changes in pleasantness or interest, across Europe, and motivate further research on the perception of brightness.

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.

Information is the resolution of uncertainty and manifests itself as patterns. Although complex, most observable phenomena are not random and instead are associated with deterministic, chaotic systems. The underlying patterns and symmetries expressed from these phenomena determine their information content and compressibility. While some patterns, such as the existence of Fourier modes, are easy to extract, advances in machine learning have enabled more comprehensive methods in feature extraction, most notably in their ability to elicit non-linear relationships. Herein we review methods concerned with the encoding and reconstruction of natural signals and how they might inform the discovery of useful transform bases. Additionally, we illustrate the efficacy of data-driven bases over generic ones in encoding information whilst discussing these developments in the context of “fourth paradigm” metrology. Toward this end, we propose that existing metrological standards and norms may need to be redefined within the context of a data-rich world.

Human circadian, neuroendocrine, and neurobehavioral responses to light are mediated primarily by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs) but they also receive input from visual photoreceptors. Relative photoreceptor contributions are irradiance- and duration-dependent but results for long-duration light exposures are limited. We constructed irradiance-response curves and action spectra for melatonin suppression and circadian resetting responses in participants exposed to 6.5-h monochromatic 420, 460, 480, 507, 555, or 620 nm light exposures initiated near the onset of nocturnal melatonin secretion. Melatonin suppression and phase resetting action spectra were best fit by a single-opsin template with lambdamax at 481 and 483 nm, respectively. Linear combinations of melanopsin (ipRGC), short-wavelength (S) cone, and combined long- and medium-wavelength (L+M) cone functions were also fit and compared. For melatonin suppression, lambdamax was 441 nm in the first quarter of the 6.5-h exposure with a second peak at 550 nm, suggesting strong initial S and L+M cone contribution. This contribution decayed over time; lambdamax was 485 nm in the final quarter of light exposure, consistent with a predominant melanopsin contribution. Similarly, for circadian resetting, lambdamax ranged from 445 nm (all three functions) to 487 nm (L+M-cone and melanopsin functions only), suggesting significant S-cone contribution, consistent with recent model findings that the first few minutes of a light exposure drive the majority of the phase resetting response. These findings suggest a possible initial strong cone contribution in driving melatonin suppression and phase resetting, followed by a dominant melanopsin contribution over longer duration light exposures.

The ipRGCs in the human eye mediate several effects on people, such as alertness and circadian rhythms. The spectral, temporal and spatial characteristics of light influence the magnitude of these effects. To facilitate the anticipation of the ipRGC-influenced light (IIL) responses in building design, new simulation tools are needed. This paper presents an extension to the open-access simulation tool Lark, available as a plugin to Grasshopper for Rhino. The proposed extension includes a set of additional options, components, and templates that incorporate currently available knowledge on the IIL responses. The applicability of the extension is demonstrated in a simulation workflow.