IGCC Series: Star Gazing in a World of Light Pollution


The International Green Construction Code (IGCC) is a model code for cities seeking to promote sustainable building practices through their building codes. The IGCC promotes transition from the current voluntary green construction certifications, like USGBC’s LEED, to mandatory green construction codes. As the most recent revisions of the IGCC are currently under review, Green Building Law Update hopes to promote awareness by examining some of the code sections.

Section 405.1 Where this section is indicated to be applicable in Table 302.1, uplight, light trespass, and glare shall be limited for all exterior lighting equipment as described in Sections 405.2 and 405.3.

405.3 Light trespass and glare. Where luminaires are mounted on buildings at locations that are within a distance to the lighting boundary, measured horizontally, that is equal to twice the height that the luminaire is mounted, such luminaires shall not exceed the applicable glare ratings specified in Table 406.3(1). All other exterior luminaires shall not exceed the applicable backlight and glare ratings specified in Table 406.3(2).

Unfortunately, star gazing i is more likely to refer to looking at pictures in tabloids than to nights spent staring at a starlit sky. If one were to try star gazing near a city tonight, one would find significantly fewer visible stars than were visible a century ago. The visibility of the stars has significantly decreased in recent years due to excess artificial light commonly referred to as light pollution.

As a recent public art installation on the Hudson River seeks to illustrate, fewer and fewer constellations are visible in New York City due to the increasing amounts of excess light forming an orange haze above The City That Never Sleeps. The installation uses solar powered LED lights to “reflect” the constellations in the river that are no longer visible because of increased light pollution.

New York City is not alone in its problem of disappearing constellations. Those who go camping can attest to the vastly greater number of visible stars away from the city lights that have become a fixture of 21st century life.

Light pollution is not only concerned with the obvious aesthetics and wasted energy. Multiple studies have been conducted to analyze the human health effects of light pollution. However, humans are not the only ones impacted. Animals, especially nocturnal ones, can be easily confused by the excess light and alter their behaviors. Have you ever had a bird chirping at an obnoxious hour of the night? You can blame the excess artificial light for your lost sleep.

Reducing light pollution is an often overlooked aspect of green building. Preventing light pollution does not equate to promoting a return to the Stone Age. Rather, green building professionals concerned with light pollution hope to encourage builders and lighting designers to focus lighting on the areas it is needed (the ground) and prevent wasted light from illuminating the sky. The IGCC advocates this approach through its light pollution control provisions which are provided as an elective code requirement.

The IGCC provides measurements limiting the amount of light fixtures can direct upward as well as the amount of light fixtures can emit horizontally that may “trespass” over property lines. These provisions also provide numerous exceptions for lighting monuments, roads, and athletic fields, among others. Despite the many exceptions and the elective nature of the light pollution control provisions, the IGCC provides a valuable framework for cities wanting to curtail the rapidly increasing rate of light pollution.

The next time you are star gazing, consider this quote by Ralph Waldo Emerson: “If the stars should appear but one night every thousand years, how man would marvel and stare.” The IGCC light pollution provision aim to ensure this never becomes a reality.

Article by Kirk Dryer, appearing courtesy Green Building Law Update.

Green Building Law Update is published to inform the construction and design industries about green building risks and legal developments. Launched in 2008, the website has served as a forum to discuss green building litigation, regulations, policy and trends.



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