Design decisions require careful consideration based on experience, best practices, inspiration and analysis of environmental parameters. Sophisticated simulation tools yield a quick grasp of a design's potential outcome, and help balance and harmonize multiple sources of information. Here, we show a typical daylighting simulation. It measures the amount of daylight that penetrates a building façade under specific seasonal conditions. These studies help us size and select glazing, specify materials, inform space planning and consequently drive overall building expression.