Annual Dynamics of Daylight Variability and Contrast: A Simulation-Based Approach to Quantifying Visual Effects in Architecture

Daylight is a dynamic source of illumination in architectural space, creating diverse and ephemeral configurations of light and shadow within the built environment. It can generate contrasting levels of brightness between distinct geometries or it can highlight smooth gradients of texture and colour within the visual field. Perceptual qualities of daylight, such as contrast and temporal variability, are essential to our understanding of both material and visual effects in architecture. But what aspects of light qualify the performance of a space? How does an architect determine how best to integrate changing light into a set of design intentions? Under the rapidly growing context of energy conscious research, we need to re-balance our definition of “performance” to include those perceptual and aesthetic aspects of light that are often disregarded by the world of simulation. Contrast is important to the definition of space and it is essential in understanding how architecture is enhanced and transformed over time by the dynamic and variable characteristics of daylight. Although there are a growing number of studies that seek to define the relationship between brightness, contrast, and lighting quality, the dynamic role of daylight within the visual field is underrepresented by existing metrics. The dynamic nature of sunlight creates a visceral connection between the occupant and his/her surrounding environment; while spatial contrast and variability are fundamental to the visual importance of architecture, architects still have to rely on intuition and experience to evaluate their dynamic effects against their intended programmatic use. A method that addresses this challenge could help designers in contextualizing the relative strength as well as the temporal stability of contrast within a given architectural space, which would open up a new dimension in architectural performance. Through an analysis of contemporary architecture from around the world, we developed a new typological language that categorizes architectural space in terms of contrast and temporal variation. Using this system of categorization, this approach proposes a new family of metrics that quantify the magnitude of contrast-based visual effects and time-based variation within daylit spaces. Through the use of time-segmented daylight renderings, a more holistic analysis of daylight performance is made possible.