Located in downtown Montreal (PQ), our project consists of a 17-story office building which is visited on a regular basis by international delegations and diplomatic corps. It thus falls in the "High ambient brightness" lighting category. The building is directly bordered by city streets and sidewalks, which are not part of this project. The property line boundary is located right at the walls on three out of four sides. All planned lighting fixtures are full cut-off as of IESNA and no interior light radiates through the building windows. However, given the location of the property line, exterior lighting fixtures will spread their light onto the adjacent sidewalks and streets. As a result, the property perimeter illumination levels measured with the lights on are more than 10% above the levels measured with the lights off (since measurements are made directly under the fixtures). There are three things to take into account in our credit interpretation. First, streets and sidewalks are already lit all night long by the city of Montreal. Second, the building\'s exterior lighting fixtures are used solely for security purposes around the building, providing the light needed by security cameras. Third, they are not producing more than 6 vertical lux at the neighbors\' windows. Given the use of this building and its high security requirements (diplomatic corps), exterior lighting is expected to remain, even if the illumination levels are met without it. Please confirm that security lighting does not have to included in our calculations and therefore, that we comply with the intent of credit SS7 to eliminate trespassing light from the building site. If not, would the use photocells to turn off exterior lighting when lighting levels are sufficient for security cameras make the project compliant with the credit requirements?
Yes, security lighting must be included in the calculations for light trespass. Due to the circumstances you describe, you may use LEED-NC v2.2 SSc8 criteria in lieu of EB SSc7 criteria for assessing compliance as it pertains to light trespass to adjacent properties. You describe your building location as consistent with Lighting Zone 4 - High Ambient Brightness (Major City Centers, Entertainment Districts). As such, the maximum allowable light trespass (per IESNA RP-33-99) onto adjacent properties is 6 lux (0.6 fc). Given your building\'s abutment to public rights of way, the 6 lux (0.6 fc) requirement may be met relative to the curb line instead of the site boundary, and drop to 0.01 fc (0.1 lux) 15 feet past the curb line per LEED v2.2 SSc8 requirements. To demonstrate compliance, submit detailed calculations and drawings showing compliance with LEED-NC v2.2 SSc8 requirements. This is in addition to verifying your LZ4 status and the absence of trespass from interior lights. Applicable Internationally; Canada.