Exterior lighting includes all ground lighting, all façade lighting, flag lighting, any rooftop or terrace lighting, and any other fixtures outside the building. Pay careful attention to exterior light fixtures and light levels at building entrances close to the LEED site boundary.

The key to achieving this credit is to find the optimum balance between lighting quality and lighting energy consumption. It is often assumed that more light is better, but a low level of uniform lighting throughout a site will eliminate the need to install bright halogen lamps that illuminate some areas and leave others dark in contrast.

For schools, the playground lights must turn off automatically after 11 p.m., with manual overrides available for special occasions. When designing exterior light-fixture layout, locate light fixtures as far from site boundary as possible.

The lighting designer develops a photometric study for exterior lighting intensity, the impact of shades and cutoff fixtures, and light trespass from the project boundary. Use the photometric study to inform any changes in the design. School projects need two sets of photometric studies, one with sports lighting only and the other without sports lighting. 

The lighting designer develops a photometric study for exterior lighting intensity, the impact of shades and cutoff fixtures, and light trespass from the project boundary. Use the photometric study to inform any changes in the design.

To determine the total power density for the project, the lighting designer tabulates all exterior space and identifies the wattage of selected fixtures to compare it with the LPD allowable by ASHRAE 90.1-2004, Exterior Lighting Section. The selected fixtures should have full shielding or cutoff to reduce light directed toward the night sky.

The lighting designer then develops the exterior lighting layout and selects fixtures that optimize light with low power use.

The lighting designer includes the design intent in Basis of Design for EAp1: Fundamental Commissioning, for all outside lighting requirements, listing minimum illuminance in footcandles, lumens, or candela for all spaces with controls, fixture requirements and design approach.

Identify the project location and IESNA-designated zone to determine the threshold for exterior lighting levels.  Utilize resources like the website www.citydata.com to identify relevant population density and appropriate designation.

Exterior lighting