Set daylighting/glare performance criteria (sDA/ASE via IES LM-83) to inform curtain wall visible light transmittance selection

Steps

1. Confirm IES LM-83's current scope on ies.org — it defines the annual climate-based daylighting metrics Spatial Daylight Autonomy (sDA, daylight sufficiency) and Annual Sunlight Exposure (ASE, glare/overlit risk proxy), adopted into green building rating systems including LEED.
2. Confirm the current LEED (or other applicable rating system) daylighting credit thresholds and simulation requirements referencing LM-83, since credit thresholds are set by the rating system, not by LM-83 itself.
3. Obtain the manufacturer's tested visible light transmittance (VLT) value for the specific proposed glazing makeup, and confirm the daylighting simulation model uses that manufacturer-provided VLT value per LM-83 guidance rather than a generic glass-type assumption.
4. Run the sDA/ASE simulation with the actual curtain wall geometry, mullion spacing, and any shading/fritting pattern proposed, since frame-to-glass ratio and frit patterns materially affect both metrics.
5. Coordinate ASE results with the interior design team on glare-mitigation measures (interior shades, fritting, tinted glass) where ASE exceeds the target threshold, since a high sDA with excessive ASE indicates a glare risk despite meeting daylight-sufficiency goals.