Energy-Efficient Outdoor Lighting Ordinance Open for Public Review

Feb. 17, 2009

After more than 3 years of work, the Intl. Dark Sky Association (ID) and Illuminating Engineering Society (IES) Joint Task Force has completed its work and approved the long-awaited Model Lighting Ordinance (MLO) for review and public comment through the parent organizations. The MLO is a breakthrough piece of civil legislation designed to be used universally by communities to promote the implementation of energy-efficient outdoor lighting.

The breakthroughs of the MLO include:

  • A single ordinance that can be used in every community with little or no community-specific language through the use of five (5) Lighting Zones of differing stringencies that tailor the MLO to address local needs and preferences
  • A prescriptive system for regulating most common lighting installations using a new rating system called BUG (Backlight-Uplight-Glare) that prevents excessive lighting and permits easy plan review and field inspection
  • A computer analysis option for complex lighting installations applies the latest research findings with respect to glare, skyglow, and light trespass and restricts designs to appropriate limits of off-site impact

The MLO is written in code language to permit easy adoption into community codes and bylaws. In addition, the MLO is consistent with the California Title 24 outdoor lighting energy code, the next generation of the IES’ Recommended Practice for Outdoor Environmental Lighting, and the next generation of ASHRAE/IES 90.1 and IECC energy codes. It is being submitted to the U.S. Green Buildings Council (USGBC) to be used for the LEED system Sustainable Sites Light Pollution Reduction Credit.

Public comments are encouraged for the next 60 days. To learn more, visit the MLO Public Review tab of the IDA website. The public comment period closes on April 10, 2009.

Task Force co-chairman James Benya says, “This MLO will permit all of the lighting recommendations of the IES to be met with currently available lighting equipment. For most situations, designs using well-shielded luminaires and good design practice will have no problem complying.”

Throughout 2008 the MLO was tested in Anchorage, AK, as part of a project developed and overseen by Nancy Clanton, a member of the task force. “We learned a lot from Anchorage’s experience, and we implemented many important details as a result,” she said. Leslie Lipstein, a city planner and task force member, added, “We made a significant effort to understand and address the challenges of communities in adopting and enforcing this lighting ordinance, and for most outdoor lighting installations, we think this MLO will be easy to use by both authorities and applicants.”

The principal regulatory element of the MLO is regulating the total amount of allowed lighting. Pete Strasser, Managing Director of the International Dark Sky Association and a task force consultant, noted, “The latest research shows that at least 10 percent of all outdoor lighting, even fully shielded lighting, ends up creating light pollution. The best way to reduce light pollution is to reduce the amount of outdoor lighting, and the MLO does just that.”

Other technical breakthroughs include using a new method for predicting skyglow contribution, developed by Dr. Chris Baddiley of England, and a new method for predicting glare recently developed by the Lighting Research Institute in Troy, New York. “We studied hundreds of lighting ordinances as part of this work. The MLO is the only ordinance that combines what has been learned from recent glare and skyglow research with the realities of practical application,” says task force member Naomi Miller.

The process of approval and release of the MLO remains with the Boards of Directors of IDA and IES. Chris Monrad, president of the Board of IDA, says, “We’ve been waiting 6 years for this document, and we’re very excited to finally get a chance to review it with our members. We hope that cities, states, federal government
agencies, and other bodies having jurisdiction over outdoor lighting practices will soon, following public review, have it in their hands to begin the process of adopting it and using it.” The IDA is already looking into companion model regulations for city street lighting, signs, and other causes of light pollution.

Said Denis Lavoie, Task Force co-chairman, “Like many communities who have written their own ordinances, we thought it would be easy and in fact, the MLO has taken much longer than we thought it would. We worked through some challenging issues related to sky glow and glare in order to have a process that has technical
credibility. The result is an ordinance that provides the flexibility for an installation to be judged based on the lighting equipment used or the characteristics of light emitted from a site.”

Dr. Ronald Gibbons, IES president, says, “the IES is very excited to be able to participate in producing a document that promotes both good lighting and minimizes the impact on the night time environment.”

A companion “User’s Guide” to the MLO is also in development for release with the final version of the MLO. To read the MLO, click here.

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