The Daylighting value will display the Daylight Factor of the selected surface(s) or façade(s). Where multiple surfaces/façades are selected or where none are selected, the average value is displayed.
Design Daylight Factor is calculated per Unit Floor Area within the Perimeter Zone for each façade/surface. It is a ratio of illuminance indoors on a horizontal work-plane to the horizontal illuminance outdoors under an overcast sky. It is a good measure for quickly comparing daylight penetration. Most guidelines recommend a value of 2 – 5% to achieve a ‘cheerfully lit’ condition and to avoid a room being both underlit or glare.
Clicking on a specific Surface will display results for just that surface alone. The results are graded by colors (grey to yellow) to provide a visual indication of low daylight (grey) to good daylight (yellow).
Daylight Factors can be compared to published guidance for your region. Guidelines usually recommend that a certain value be achieved for a certain percentage of critical task zones.