Office Spaces in a Cool Temperate Climate: Impact of Architectural Solutions on Daylight Quality in Interiors, in the Context of User Well-Being and Circadian Rhythm

Interior space quality in certified office buildings is key in supporting the health and well-being of occupants. Daylight, which regulates the human circadian rhythm and affects physiological processes and productivity, is crucial. This study’s objective was to determine how a building’s architecture and selected elements of its interior such as partitions and finishing material parameters affect sunlight distribution in workspaces and its biological effectiveness, as measured using Equivalent Melanopic Lux (EML). The environment’s impact on the non-visual potential of a space was also assessed (in relation to the M/P ratio). To achieve these objectives, we used a 3D model of an office building floor to simulate natural lighting in various configurations, for a cool temperate climate using Solemma’s ALFA 2025 software. This research was conducted using simulations only, with no in situ measurements. The study assessed melanopic light intensity for specific zones and workstation groups. The impact of ceiling colors and the five colors given to partitions of different heights located between desks was also determined. The study evaluated the relationship between photopic and melanopic intensity and found that, as the height of the partitions increased, especially with cloudy skies, the importance of these planes’ colors increased. Blues had a positive effect on the space’s non-visual potential, while oranges showed significant decreases in EML relative to lux, by up to 25%. This research underscores the importance of light’s non-visual impact and the consideration of these aspects at every design stage, especially interior design, to provide a comfortable work environment and its long-term benefits. We also proposed natural light exposition optimization strategies that can support proper circadian rhythm.