Daylight Metrics Update: New Provisions in LM-83-23 Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE)

IES Lighting Measurements (LM) 83-23, Approved Method: IES Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) recently underwent significant revisions and ANSI certification. LM-83-23 describes the IES approved method for computing annualized climate-based metrics for daylight sufficiency (sDA) and for excessive sunlight exposure in buildings (ASE). It provides a common reference standard for daylighting performance across building typologies and climate regions. Learn from Daylighting Metrics Committee members about important changes made in the 2023 version and their rationale, along with their implications for daylighting design and analysis. Perspectives and discussion regarding the application of LM-83-23 and an outlook toward the adoption of updated methods in software tools will be included.