This credit has two compliance options, which means your team has some flexibility in how it chooses to demonstrate compliance.
Option 1 deals directly with your exterior fixtures (both luminaires and illuminated signage) and the lamps you use. Option 2 assesses your building’s contribution to light pollution through nighttime illumination measurements taken around the project boundary.
If some of your exterior fixtures can’t comply with Option 1, there’s still a chance that your building can comply with Option 2. Unfortunately, there’s no good way to know whether you’ll comply with Option 2 except to perform the actual measurements, so teams often try to comply with Option 1 first.
This credit is easier to earn compared to LEED 2009, as the interior lighting component has been removed entirely. Teams now need to be concerned with lights on the building exterior only.
Yes. For Option 1, illuminated signage on the building exterior must have compliant shielding unless the sum of the mean lamp lumens is under 2,500. If you have exterior signage that doesn’t meet either of those requirements (and you can’t perform retrofits), you can still potentially earn the credit by pursuing Option 2 Perimeter Measurements.
Yes. Exterior roof lighting must comply with the credit requirements.
All exterior lighting and illuminated signage must comply with the credit requirements, even if is not owned or controlled by the building management. Option 2 can be used to demonstrate compliance if some or all of your exterior lighting cannot meet the requirements of Option 1.
To increase night sky access, improve nighttime visibility, and reduce the consequences of development for wildlife and people.
Shield all exterior fixtures (where the sum of the mean lamp lumens for that fixture exceeds 2,500) such that the installed fixtures do not directly emit any light at a vertical angle more than 90 degrees from straight down.
Measure the night illumination levels at regularly spaced points on the project boundary, taking the measurements with the building’s exterior and site lights both on and off. At least eight measurements are required, at a maximum spacing of 100 feet (30 meters) apart. The illumination level measured with the lights on must not be more than 20% above the level measured with the lights off.
There are no comments yet. Start the discussion!
PE, LEED AP
Copyright 2017 – BuildingGreen, Inc.