Abstract
Mean room surface exitance (MRSE) is a metric proposed to assess lighting quantity within a new design methodology focused on ambient and target illumination. This research builds upon findings from previous research examining the suitability of MRSE as a metric for assessing ambient illumination brightness levels and illumination adequacy for offices. An experiment was conducted to investigate a finding from previous studies that a linear relationship existed between perceived adequacy of illumination (PAI) and MRSE. It was found that the relationship diverges from linear once the scale of MRSE values is extended above the 100 lm/m2. This study also suggests a relationship between spatial brightness and MRSE for an extended range of MRSE values up to 1400 lm/m2. The findings from this research provide insight into a tentative range of MRSE levels that may be suitable for an office environment.