Our project is a 1.2 million SF Medical Science Building renovation and expansion for an urban university campus. The program consists of research and teaching laboratories, lab support areas, offices, conference rooms, lecture halls, classrooms, libraries, food service, and public areas. There are two adjacent major urban hospitals and no adjacent residential neighborhoods. This medical science building and all the adjacent hospital facilities in this area are 24 hour operations. The street lights along the block are cobraheads so there is a significant ambient light level. We are requesting an interpretation for the selection of the exterior luminaires for pedestrian walkways and plaza areas. The intent of SS Cr. 8 v2.1 states "Eliminate light trespass from the building and site, improve night sky access and reduce development impact on nocturnal environments." The credit requires luminaires with more than 3500 initial lamp lumens to meet the Full Cutoff Classification. It also requires zero light to cross project or real campus property boundaries and zero uplight. Due to the high ambient light levels in the vicinity of the site, we are requesting a variance to use a luminaire with a small amount of uplight. This luminaire meets the requirements of other current industry standards where environmental zone is taken into effect with respect to light pollution. Within this setting, current industry standards would allow "up to 5% of the total initial designed fixture lumens above 90 degrees" and "a maximum initial illuminance value of no greater that 0.20 horizontal and vertical footcandles at the site boundary and must drop off to 0.01 footcandles within 15 feet beyond the site". The luminaire we are requesting to use is classified as Cutoff and has only 0.5% initial lamp lumens and 1.2% of the total initial designed fixture lumens above 90 degrees from nadir. The luminaire provides no direct glare. Additionally, this luminaire has been selected to be the new Campus Exterior Lighting Standard (meeting the newer LEED NC v2.2 for this credit). All future campus projects will use this fixture. The University desires to use it for this v2.1 project at this time. The use of this one luminaire across the campus offers benefits of sustainability with respect to maintenance practices by reducing the quantity of spare fixtures, components and lamps needed. It also provides campus design continuity in their open spaces.
The project is located within an urban campus in an area of high ambient brightness. Fixtures selected for the site, as a part of the campus standard, are classified as cutoff fixtures with 1.2% of the total fixture lumens being emitted above 90 degrees from nadir. It is assumed from the submitted narrative that these fixtures exceed 3,500 initial lamp lumens, which would require them to be full-cutoff in order to meet the requirements of this credit. The narrative notes that these fixtures have been selected by the campus to comply with the requirements set forth under LEED-NC v2.2 and are requesting that this fixture be allowed for this specific case. Although the fixture does not meet the specific requirements of v2.1, the context in which it is being used appears to meet the intent of this credit. In order to demonstrate compliance with the credit\'s intent, the project team should submit detailed documents, including a photometric report for the specific luminaire, to illustrate the ambient site conditions and to confirm that the overall site illumination design and fixture selection meets the intent of this credit. It may also be beneficial for the project team to explore the use of NC v2.2 for the overall project submittal. Applicable Internationally.