One key method to improve the energy efficiency of a building is to enhance daylight levels, which reduces the need for artificial lighting. Elevated daylight levels are also associated with increased productivity and well-being of building occupants. Daylight levels are inversely proportional to the building compactness, where shallow floorplates and elongated buildings are associated with higher daylight levels. However, creating buildings that have more natural light comes with a greater construction cost due to larger envelope areas as well as greater operating costs due to the energy loss through the exterior envelope area. This research identifies the basic design strategies that best optimize two opposing trends: enhancing daylighting in buildings while reducing the amount of energy transfer loss through the building envelope. We analyzed a sample of fifty floorplates of key buildings of the 20th century considered best practice examples of architectural precedents. We inquired about the effect of building size on the complex relationship between natural lighting and building compactness, which is linked to cost. First, all the buildings are scaled and brought to the same floorplate size in order to evaluate the effect of the building’s formal typology on daylighting. Second, the shapes of building floorplates are analyzed and categorized according to their compactness and fragmentation. The statistical analysis of the sample enables the identification of the cases that perform best regarding both daylight levels and the extent of the outer envelope. The findings can be used to inform the design of buildings with important implications for the sustainability of the built environment.
Welch et al. (Sun,) studied this question.