Calculation Metrics
Vertical Sky Component (VSC)
“Is the ratio of the direct sky illuminance falling on the vertical wall at a reference point (usually the centre of the window), to the simultaneous horizontal illuminance under an unobstructed sky.” Based on a CIE overcast sky and does not include reflected light.
Daylight Distribution (DD)
A calculation which plots a contour on the working plane of the area from which no sky can be seen. Also known as No Sky Line (NSL).
Average Daylight Factor (ADF, BRE 2nd Edition)
A Ratio of total daylight flux incident on the working plane to the area of the working plane, expressed as a percentage of the outdoor illuminance on a horizontal plane due to an unobstructed CIE standard overcast sky.
Annual Probable Sunlight Hours (APSH)
Measures the amount of direct sunlight on a given window for an annual period.
Two Hours Sunlight to Amenity
Measures the amount of direct sunlight for a given amenity on a specific date.
Time in Shadow
Calculates the amount of time a particular area is within Shadow on a specific date.
Sunlight Exposure (SE)
Sum of the time that a given window receives direct sunlight on a specific date.
Daylight Factor (DF)
Is the ratio of total daylight illuminance at a reference point on the working plane within a space to outdoor illuminance on a horizontal plane due to an unobstructed CIE standard overcast sky.
Illuminance Method (sDA)
Calculates the illuminance at a point on the working plane in a space for each daylight hour, for which a target illuminance should be achieved across at least half of the reference plane, for at least half of the daylight hours.
View Out
An assessment which looks for the three distinct layers (Ground, Landscape and Sky) as well as horizontal sight angles and outside distance to view.
Daylight Glare Probability (DGP)
Highlights areas that may receive glare in spaces where the activities are comparable to reading, writing or using display devices and the occupants are not able to choose position and viewing direction
Potential Solar Glare
Identifies potential solar glare based on view direction, proposed materials that could produce glare and its orientation.
Solar Radiation
Used for Photovoltaics (PV) systems to estimate the amount of energy (kWh/m2) emitted by the Sun, based on a climate file.
Useful Daylight Illuminance (UDI)
Calculates the percentage of occupied time where a point in a space reaches a target range of daylight illuminances.
Annual Sunlight Exposure (ASE)
Calculates the percentage of a space that exceeds a specific amount of direct sunlight for a specified numbers of her per year.
Transient Shadow
Produces a series of shadows at a specified time interval on a specific date.
Rights Of Light
A calculation which plots a 0.2% sky factor contour on the working plane both before and after the proposed obstruction.
