Exposure to light relevantly influences human circadian rhythms, affecting not only visual perception but also physical and mental health. This thesis explores the role of architectural lighting on human health and well-being within a controlled Live-in Lab environment, focusing particularly on twilight exposure and its effects on circadian rhythms and sleep patterns. Employing a combination of environmental sensors and sleep diaries, the study quantifies light exposure and investigates its association with sleep disturbances and overall daily well-being. 

The findings reveal a notable misalignment between the prevailing lighting conditions and the optimal settings for supporting natural circadian rhythms. This misalignment underscores the necessity for architectural designs that more effectively integrate natural light cycles, particularly in regions with relevant seasonal variations in daylight, such as northern latitudes. Based on these insights, the thesis recommends adopting twilight simulation technologies to enhance sleep quality and better align circadian rhythms with other light patterns that are not naturally synchronized with the extreme conditions in the Nordics. 

The research contributes to the field by providing empirical evidence supporting the development of lighting strategies that promote healthier living environments, emphasizing the crucial role of lighting design in enhancing well-being. The recommendations offered aim to guide future architectural practices in creating spaces that not only meet aesthetic and functional requirements but also foster health and sustainability.