Daylighting Impacts on Human Performance in School

Abstract

The purpose of this study was to see if we could demonstrate a clear relationship between the presence of daylight and human performance in buildings. In this study we used a statistical technique called multivariate regression analysis, which analyzes the importance and impact of many variables simultaneously. The performance data used were gathered from three school districts. This analysis allowed us to estimate the effect of a wide number of variables and to determine which variables have no significant effect. Using this method, we established a statistically compelling connection between the presence of daylight and student performance. The implications of the results of this study extend beyond the educational sector. We believe the conclusions may be transferable to other types of buildings, such as offices and factories, since it is really human performance we investigated. If daylighting enhances the performance of children in schools, it is not too large a stretch to suppose that it might also enhance the performance of adults in office buildings. Background Up through the 1950s and into the early 60s almost all school buildings in the United States were daylit, i.e., they were intentionally designed to provide sufficient interior daylight for normal daytime visual tasks. However, by the mid-1960s a number of forces came into conflict with the concept of daylit classrooms. Engineers, asked to provide air conditioning in classrooms, argued against the use of large expanses of glass and high ceilings. Educational theorists argued that a more flexible arrangement of open classrooms, grouped in large openplan buildings, would encourage team-teaching and creative learning. Construction economists argued that schools could be built more inexpensively on smaller sites if the classrooms could be grouped together in modules, without constraints on solar orientation. Increasingly, schools were built with little or no daylight provided to the classrooms. In 1974, Belinda Collins of the National Bureau of Standards and Technology (NIST) conducted a major literature review of available research on windows, and concluded there was no conclusive evidence that windows were a necessary component of classrooms. 1 More recently, daylighting has been advocated as a way to reduce lighting energy use in schools and other non-residential buildings. Turning off electric lights when sufficient daylight is available can save a significant amount of lighting energy costs. Because daylight introduces less heat into a building than the equivalent amount of electric light, cooling costs can also be reduced with appropriate daylight design. 2