Daylight Metrics

Licaso will compute all of the following daylight metrics. Specific settings for each metric are found in the View Display Settings panel.

Metric Notation Units Description
Illuminance E lux, fc Illuminance at each point for each date/time sample.
Basic Daylight Autonomy DA % Fraction of occupied hours per year where the illuminance at a point is greater than or equal to a target threshold value.
Continuous Daylight Autonomy cDA % Fraction of occupied hours per year where the illuminance at a point is greater than or equal to a target threshold value and where partial credit is given where the illuminance is less than the threshold value.
Maximum Daylight Autonomy mDA (maxDA) % Fraction of occupied hours per year where the illuminance at a point is greater than a maximum threshold value.
Minimum Daylight Autonomy minDA % Fraction of occupied hours per year where the illuminance at a point is less than a minimum threshold value.
Spatial Daylight Autonomy sDA % Fraction of area where Daylight Autonomy is greater than or equal to a threshold value. May apply to any of the daylight autonomy metrics (DA, cDA, UDI, etc).
Useful Daylight Illuminance (Acceptable) UDI (UDI-a) % Fraction of occupied hours per year where the illuminance at a point is (inclusive) between minimum and maximum threshold values.
Useful Daylight Illuminance (Supplementary) UDI (UDI-s) % Fraction of occupied hours per year where the illuminance at a point is below the minimum threshold value.
Useful Daylight Illuminance (Excessive) UDI (UDI-e) % Fraction of occupied hours per year where the illuminance at a point is above the maximum threshold value.
Annual Daylight Exposure ADE lx-hours/year fc-hours/year The cumulative amount of visible light incident on a point per year.
Annual Sunlight Exposure ASE hours/year Number of hours per year a point receives direct sunlight greater than a threshold value.
Spatial Annual Sunlight Exposure sASE % Fraction of area where Annual Sunlight Exposure is greater than a threshold value.