855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 499

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  • Achieve a UGR of 19 or lower using the software modeling calculations of the designed lighting. Modeling must be performed as outlined in the “NEMA White Paper on Unified Glare Rating” [162] .

Color rendering Use luminaires that have a color rendering index of at least 90, or that meet the color rendering requirements in Table 1, in accordance with Illuminating Engineering Society (IES) TM-30-20 .

Table 1. Color rendering requirements using TM-30-20

MeasureCol2Requirement
Fidelity indexRf78 or higher
Gamut indexRg95 or higher
Red Local Chroma ShiftRcs,h1-1% to 15%

AND/OR

PATH 3. PROXIMITY TO WINDOWS FOR DAYLIGHT ACCESS (1 POINT)

Design the building floorplates and interior layout to provide at least 30% of the regularly occupied area to be within a 20-foot (six-meter) horizontal distance of envelope glazing. The glazing must have a visible light transmittance above 40%. Regularly occupied areas with visual obstructions (incapable of providing a view to envelope glazing) should be excluded from the compliant area.

OR

PATH 4. DAYLIGHT SIMULATION (1–4 POINTS)

Perform a daylight simulation analysis for the project to understand and optimize access to daylight and visual comfort. Use the calculation protocols in IES LM-83-23 with the following clarifications:

  • Calculate s patial daylight autonomy300/50% (sDA300/50%) and annual sunlight exposure1000,250 (ASE1000,250) as defined in IES LM-83-23 for each regularly occupied space in the project. sDA 150/50% may be used for areas without visual tasks with design targets of 225 lux.

  • For any regularly occupied spaces with ASEnet(1000,250h) greater than 20%, identify how the space is designed to address glare.

162 “NEMA White Paper on Unified Glare Rating”, NEMA, (2021), accessed March 21, 2025, https://www.nema.org/standards/view/white-paper-on-unified-glare-rating-(ugr)

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 489