To achieve the Sustainable Sites Credit, Light Pollution Reduction, Option 1. BUG Rating Method,
projects must demonstrate that all luminaires meet acceptable fixture ratings for the project’s Model
Lighting Ordnance (MLO) lighting zone. The MLO lighting zone is determined by the site-specific
characteristics and the definitions provided in the IES/IDA MLO User Guide1. The fixture ratings are
based on the backlight-uplight-glare (BUG) system, which measures the amount of light emitted in
different directions by a luminaire, as defined in IES TM-15-11, Addendum A2. The maximum
allowable ratings for each lighting zone are given in Table 1 of the credit language3. Reference:
IES/IDA MLO User Guide; IES TM-15-11, Addendum A; Light pollution reduction
