Dramatic changes in technology
New lighting technology has dramatically changed exterior lighting in the last five years. Until recently, high-intensity discharge (HID) lamps dominated the marketplace due to their low cost and wide light coverage (allowing the use of fewer fixtures). Those applications, however, contribute to light pollution, which wastes energy, interferes with biological functions of many species, and veils the night sky dome.
LED lighting is now cost-effective and increasingly common on all outdoor lighting projects—not just LEED projects. These fixtures still cost more than a conventional fixture, but those prices are approaching parity, and energy and maintenance costs are much lower. LED fixtures last for tens of thousands of hours, and they are inherently better at focusing light where it is needed. Simple payback of as little as two years is now possible, even when more fixtures might be needed to cover the same area. Within the next five years, LED outdoor lighting will likely become standard—with or without LEED. That would simplify credit compliance and make lighting a design choice, not a budgetary restriction.
Soft costs for documentation
As with other LEED credits, there are some “soft” costs for documentation. LEED v4 uses the “BUG rating” (for backlight, uplight, and glare) as a prescriptive option to earn this credit, which will likely make the detailed calculations previously required less common for projects. Designers will only have to look up and calculate BUG ratings for each fixture.
In LEED v4, interior lighting requirements have been removed from this credit, simplifying the requirements and cost considerations.
LTc7: Reduced Parking Footprint
EAp2/c2: Energy Performance
EQc6: Interior Lighting