Sunlight is a multidimensional phenomenon that influences occupant’s comfort and well-being through its dynamic visual and thermal attributes. Previous studies suggested that the presence of sunlight patterns in space was cheering and visually interesting, which could improve visual comfort and space quality. However, it remains unclear what the attributes of visually interesting sunlight patterns are, and whether their visual interest influences visual comfort. This dissertation aims to answer three main questions: (1) is there a difference in visual interest and mood response among different projected light patterns? (2) How do sunlight patterns of different geometries influence visual interest and visual comfort in offices? And (3) what are the geometrical attributes of sunlight patterns that should be implemented in office spaces? To address these questions, a series of four studies were conducted. The first two studies extended empirical findings on visual interest and mood responses elicited by varying complexities of fractal and non-fractal light patterns projected on walls and floors of an interior space. These two studies determined which patterns to be further examined in Studies 3 and 4, which investigated the visual comfort, visual interest of sunlight patterns, and view quality under three different window conditions in office spaces. The results of studies 1 and 2 suggested that fractal light patterns of medium to medium-high complexity, quantified by the fractal dimension in the range (D=1.5-1.7), were significantly more visually interesting than other patterns. Both studies found that fractal compared to non-fractal light patterns provided a better balance between relaxation and excitement. Study 3 found that the fractal pattern was associated with a significant increase in visual comfort, compared to the striped pattern, though the difference in visual interest between the two patterns was not statistically significant. Study 4 found that the effect of the fractal pattern on visual comfort, visual interest of sunlight patterns, and view quality was dependent on occupant’s view direction and façade orientation. These findings can have implications for the design and control of facade systems to improve occupant’s visual comfort, interest, and view quality in work environments. This dissertation includes both previously published/unpublished and co-authored material. / 2019-01-27

Stockholm’s subway system is considered one of the longest art galleries in the world.Each station has its own identity, but at the same time, all metro stations have the sameuniform functional light approach.This light could not prevent the passengers from gathering and walking randomlyat the subway station’s platform. Moreover, the uniform light is neglecting the artwork onthe station’s platform; hence, this could lead to losing the identity feature of the station. Ingeneral, the demand for using public transportation in sustainable urban cities is increasing.This thesis studies how to use light as an information giver for the passengers on the subwaystation platform:By creating light safety zones and by enhancing the wayfinding to minimize conflict points.From the result of the questionnaire and the observations in two case studies, adesign principle with eight parameters has been developed to be applied in new lightingdesign for the T-Centralen platform station. It aims to restore the identity of the station,and create different zones at the T-Centralen subway platform, to enhance the movementof the passengers and to make it more organized by combining different layers of functional,atmospheric and dynamic light.