Barbara Matusiak

The Impact of Window Form on the Size Impression of the Room—Full-Scale Studies

Full-scale studies of a small room were carried out at Norwegian University of Science and Technology, Norway, to find out in which way the form of window(s) influence the size impression of a little room. Care was also taken to find out if the impression is due to the form of the window alone, daylight falling through it, or to both. The results indicate that the impression of room dimensions depends on window form, even if the total glazing area is equal. Generally, vertical windows make that the room appear higher, horizontal make it wider. The visual impression of the room depends also to a high degree on the placing of the window in relation to the neighboring surfaces: sidewalls, floor and ceiling. The window adjacent to a sidewall contributes to higher luminance of this wall, it appears as being further away from the observer; the room appears as wider. The same principle is true for windows adjacent to the ceiling or floor. They contribute to increasing the impression of height. The study was carried in rooms having high reflectances on all surfaces, the enlarging effect of the window adjacent to the neighboring surface may not be that clear in rooms having dark surfaces.

Analysis of Stereoscopic Images as a New Method for Daylighting Studies

This article presents the comparison analysis and results of an experiment designed with two presentation modes: real environments and stereoscopic images. The aim of this article is of a methodological nature, with a main objective of analyzing the usability of stereoscopic image presentation as a research tool to evaluate the daylight impact on the perceived architectural quality of small rooms. Twenty-six participants evaluated 12 different stimuli, divided in equal parts between real rooms and stereoscopic images. The stimuli were two similar rooms of different achromatic-colored surfaces (white and black) with three different daylight openings in each room. The participants assessed nine architectural quality attributes on a semantic differential scale. A pragmatic statistical approach (Bland-Altman Approach) for assessing agreement between two methods was used. Results suggest that stereoscopic image presentation is an accurate method to be used when evaluating all nine attributes in the white room and nearly all attributes in the black room.

Luminance-Based Measures of Contour Distinctness of 3D Objects as a Component of Light Modeling

ABSTRACT This article presents possible luminance-based measures of contour distinctness of 3D objects observed under real daylight conditions. Contour distinctness is considered here as a component of the broader concept of light modeling and is a significant metric of quality lighting. We set up an experiment where different measures of contour distinctness were studied with the help of high dynamic range imaging techniques. Measures obtained from the luminance maps were brought into correlation with survey results from 32 subjects. The analytical comparison showed that the contrast measurement (calculated with the Weber formula), luminance ratio between average luminance of the object and average luminance of the background, mean of paired point luminance ratio (mean point LR) measurements around the contour of the object, and percentage of the invisible part of the contour are good predictors for contour distinctness of the observed 3D objects. The proposed measures expressed in numerical values are comprehensive and easy to obtain and can be practically applicable after the further development.

Width or Height? Which has the Strongest Impact on the Size Impression of Rooms? Results from Full-Scale Studies and Computer Simulations

Abstract Full-scale studies of small rooms were conducted to find out whether width or height has a stronger influence on the size impression of the room. The study also investigated whether this question can be answered using computer simulation. Two simulation programs were used in the study: ArchiCAD and Radiance, the most advanced lighting simulation program. The results from full-scale studies carried out with school children indicate that width has a stronger positive impact on size impression than height. The difference is much more evident in richly daylit rooms than in gloomy ones. However, a similar full-scale study carried with architectural students did not support this finding. It is not clear if the difference between school children and architecture students is caused by the eye height of the observers, the unique experience with architectural space that architect students have, or both. Computer simulation studies showed that the size impression of the appearance of a room by looking at virtually generated pictures might be different from the size impression of the room built in full-scale. The main question addressed by the paper—width or height—cannot be answered with the aid of computer simulations alone.

Luminance-Based Measures of Shape and Detail Distinctness of 3D Objects as Important Predictors of Light Modeling Concept. Results of a Full-Scale Study Pairing Proposed Measures with Subjective Responses

ABSTRACT Nowadays it is very common to discuss the various aspects of lighting within a framework of energy efficiency. In addition, the questions concerning lighting quality and occupants’ comfort are another topic for active studies and debates. In the current investigation we tested one aspect of lighting quality—that is, light modeling—with the help of a luminance mapping technique. Here the degree of a 3D object’s shape and detail distinctness are associated with modeling quality; that is, directly related to the light modeling concept. The aim of the study was to comprehend whether luminance-based design as a method, most perception oriented among others, could be applicable for the evaluation and prediction of the visibility of the shape and details of real 3D objects observed by people under daylight conditions and, further, to suggest luminance-based measures that can be developed into indicators of shape and details distinctness. Ordinal regression analysis of the survey results paired with several measures based on luminance values was performed. The tested measures were luminance ratio, mean luminance of the object, standard deviation of the luminances of the object, and the ratio between the highest luminance value of the object and mean luminance of the object. Among all of these measures the first three have the strongest correlations with subjective perception of 3D objects’ shape and detail distinctness.

Aesthetic perception of a small office with different daylighting systems

The quality of a lit environment cannot be deduced solely from the quantity of light. Therefore, daylighting studies should not only be focused on the usage of lighting metrics but should also consider the aesthetic experience. This paper examines the influence of daylighting systems on the aesthetic perception of a small office. One single side lit office was equipped with four different daylighting systems (white blinds, high-reflecting blinds, hybrid light shelf and mirror light shelf) under two sky conditions (clear sky and overcast sky). In total, eight stimuli were captured and presented via stereoscopic images. Fifty participants evaluated the images using the semantic differential scale to rate nine architectural quality attributes. The results from MANOVA indicated that both the daylighting systems and the type of sky had an effect on the aesthetic attributes, and that the significant interaction effect suggested that the aesthetic perception of a daylighting system depends on the type of sky. Subsequent statistical findings showed that the high-reflecting blinds comprised the daylighting system that scored highest in nearly all attributes under both clear and overcast sky conditions.

How we evaluate the view out through the window

This paper describes a study about factors impacting the perceived quality of the view out of the office window that was carried out in Trondheim, Norway, in 2013. A total of 106 subjects were visited in their respective working environments. The subjects were asked to evaluate the quality of the view from their typical working (sitting) position on a four-point scale: not satisfactory, satisfactory, good, excellent. The view was documented by taking pictures from the subjects eye position in the direction of the window(s). A regression analysis shows that the view quality evaluated by subjects is best predicted by the view distance, the number of view layers, the quality of the landscape/elements and the composition of the view. The view width, the extent of greenery in the view, the presence of water, the weather conditions, or gender and age were not found to contribute additionally to the perceived view quality.

Categorisation of Colour Terms Using New Validation Tools: A Case Study and Implications:

This article elaborates on the results of a field experiment conducted among speakers of the Chakali language, spoken in northern Ghana. In the original study, the Color-aid Corporation Chart was used to perform the focal task in which consultants were asked to point at a single colour tile on the chart. However, data from the focal task could not be analysed since the Color-aid tiles had not yet been converted into numerical values set forth by the Commission internationale de l’éclairage (CIE). In this study, the full set of 314 Color-aid tiles were measured for chromaticity and converted into the CIE values at the Daylight Laboratory of the Norwegian University of Science and Technology. This article presents the conversion methodology and makes the results of the measurements, which are available in the Online Appendix. We argue that some visual-perception terms cannot be reliably ascribed to colour categories established by the Color-aid Corporation. This suggests that the ideophonic expressions in the dataset do not denote ‘colours’, as categorised in the Color-aid system, as it was impossible to average the consultants’ data into a CIE chromaticity diagram, illustrate the phenomena on the Natural Colour System (NCS) Circle and Triangle diagrams, and conduct a statistical analysis. One of the implications of this study is that a line between a visual-perception term and a colour term could be systematically established using a method with predefined categorical thresholds.

Verification of the Accuracy of the Luminance-Based Metrics of Contour, Shape, and Detail Distinctness of 3D Object in Simulated Daylit Scene by Numerical Comparison with Photographed HDR Images

ABSTRACT This study verifies the accuracy of previously developed luminance-based metrics of light modeling (that is, the distinctness of contour, shape, and details of daylit 3D objects) through comparison of numerical values of the metrics obtained from photographed and simulated high dynamic range (HDR) images. The analysis of the luminance data of eight photographed and eight simulated HDR images of Venetian masks showed that the mean relative error of all tested metrics was 14.78%. The minimum average relative error was 7.91%, and the maximum error (found for only one metric) was 27.75%. The glossy objects had higher error rates than matte objects tested within the experiment. Additionally, the variation among luminance-based metrics obtained from simulated and photographed HDR images was compared with variation among illuminance-based metrics. It became evident that luminance-based metrics (consequently color and specularity dependent) showed considerable variation among examined masks, affirming the impact of color and specularity on visibility of contour, shape, and detail. Though the tested luminance-based metrics may need further investigation in experimental conditions that differ from those used in this study, it is clear that they could be applied both with photographed and simulated luminance maps with precision of about 15%. Experimental results confirm the robustness of the metrics and encourage use of the luminance-based light modeling metrics in computer lighting simulations.

Low-energy house, back to the ‘årestue’: a thought experiment about low-energy houses

In this article the thought experiment method is used to demonstrate what can result from taking the goal of energy efficiency to extreme measures. The point of departure for this thought experiment is the assumption that in order to minimize energy needs in Norwegian buildings the following three principles are to be followed: minimize building volume per person, maximize building shape compactness and use a well-isolated building envelope with smartly designed windows. The conclusion of the thought experiment applied for single-family houses leads to the building form similar to the årestue, the simplest building shape common in Scandinavian villages up until the 18th century, having an open fireplace in the middle of the floor and an opening in the roof to let the smoke out and the daylight in. The thought experiment exposes a latent wisdom buried here in the old and well-adjusted architecture of the årestue, an anonymous architecture that emerged in times when human beings could not afford to waste resources. A modern version of the Norwegian low-energy, single family house would have been built using modern materials and advanced technology, but the shape of the house would have been surprisingly similar.