SS Credit 8: Light Pollution Reduction

Hello all,

Today's topic for LEED Construction is the final point awarded under the Sustainable Sites category for LEED point rating system. This section is the most important In my mind and takes an integrated design approach early on for success.

"Intent - Minimize light trespass from the building and site, reduce sky-glow to increase night sky access, improve nighttime visibility through glare reduction, and reduce development impact on nocturnal environments." from LEED Version 2.2

The Sustainable sites category has 20 percent of the total amount of points needed for Platinum rating under the USGBC (United States Green Building Council).

The other section that is close to this 20 percent is Indoor Environmental Quality and a close third is for Materials & Resources. Focus on these areas for success with LEED rating.

Sustainable Sites section sets the tone for the project.

This section defines different requirements for different areas. The same light restriction requirements for suburban rural areas are not going to follow the same as lets say Times Square New York.

Even urban areas that do have more need for exterior lighting can reduce the impact on neighbors and the sky for star gazing by selecting light fixtures that provide light in the areas that are needed and not overlap areas that did not sign up for it.

Light respect is another way to look at it. No one likes having a flash light pointed in their eye so remember light can offend and it also uses energy so use it specifically and sparingly.

Lighting manufacturers and light vendors are providing architects and builders with photometric charts showing the light lumen's and path given the fixture and position off the building. This is needed for a LEED review and to qualify the design intent for SS Credit 8. Typically you can ask a manufacturer for a Photometric chart of any light fixture to determine how much light given its position away will provide. This building footprint photometric chart can really identify areas in the lighting concept that may have negative effects for the surrounding areas. Try to select lighting fixtures that limit the cast vertically if the light is not intended to be placed there.

Please see the LEED for New Construction Version 2.2 for more detail information on LEED Credit 8 - Light Pollution Reduction.

and as always

Remember to Tread Lightly or Less

Be Green

Be Happy

Eric H. Gjerde AIA
Architect