Visualizing Daylight Factor & Illuminance Levels

Sefaira recently released two upgrades that expanded the scope and flexibility of our daylighting analysis: Daylight Factor visualization, and adjustable lux thresholds for Spatial Daylight Autonomy.

These additions further extend Sefaira’s cloud deployment of DAYSIM and Radiance-based rapid daylight analysis, and allow architects to gain rapid insight into the daylight performance of their buildings while they design.

Daylight Factor Visualization

Architects can now toggle quickly between Daylight Factor and Spatial Daylight Autonomy visualizations. This addition helps architects get early feedback when trying to hit specific daylighting targets.

What’s the difference between these two metrics? As you can see from the image below, the Daylight Factor and Spatial Daylight Autonomy visualizations can look quite different. That’s because Daylight Factor is a simple ratio of exterior and interior illuminance under an overcast sky. Spatial Daylight Autonomy, on the other hand, utilizes location-based weather data over the course of an entire year. (For more detail on these metrics, see our post on Measuring Daylight.)

Adjustable Illuminance Levels

Architects can also adjust the illumination threshold for the Spatial Daylight Autonomy visualization. This visual shows the percent of occupied hours when work planes receive enough light. The threshold for “enough light” is initially set to 300 lux — a standard level for an office — but can be quickly adjusted, using built-in benchmarks as a guide.