This project is located in a downtown area with a fair amount of ambient brightness. For a portion of the site, the design team desires to uplight a grove of trees immediately adjacent to the building and some other trees intermittently along one of the main paths through the site. The lights will be narrow or medium floods that keep the lumens below the canopy to fewer than 3500 lumens.As noted in the LEED Credit Ruling dated 3/14/03, some uplighting is allowed as long as the project adheres to all of the other conditions stated in that Credit Ruling.The project will be able to demonstrate that all other Light Pollution Reduction Credit requirements are met, including (1) full cut off luminaires for lamps over 3500 initial lumens and shielding for those over 1000 initial lumens. (2)Use of lighting controls to turn off lighting after hours and/or during post curfew periods. (3) Commissioning of lighting controls .The design team is anticipating minimal use of the uplighting and is setting our curfew for those luminaires at 8:00pm Standard Time and by 10:00pm during Daylight savings time. In addition there may be special events in which the uplighting remains on beyond the curfew specified above. The design team is proposing this schedule, but would be amenable to another schedule if the Credit Ruling Committee deemed one to be more appropriate.Please confirm that this schedule and approach are consistent with the USGBC\'s previous credit ruling on this subject.
Yes, your approach is consistent with previous guidance. Per the Credit Ruling dated 3/14/2003, limited uplighting is allowed under LEED Version 2.1 in areas of high ambient brightness. Table 1 on page 70 of the LEED v2.1 Reference Guide, which is adapted from the referenced standard (IESNA RP-33-99), describes light trespass limitations for four distinct environmental zones. The project team states that the project is in an area that has a "fair amount of ambient brightness". The project team would first have to document that the building is indeed in an environmental zone of high ambient brightness.Once that requirement is met, the project team would earn the credit if ALL of the requirements outlined and the cited Credit Ruling are met AND lighting is limited to 0.2 watts/SF of object footprint (canopy area) - as currently proposed for the lighting requirements of ASHRAE 90.1-2004. Summarize the details in a narrative for this credit in your LEED application and confirm that the installed fixtures and lamps are the same as those specified. Applicable Internationally.