November 12, 2024
DarkSky Introduces Streamlined Lighting Ordinance Templates
New template offers local governments concise, actionable steps for reducing light pollution
DarkSky International, a global organization dedicated to combating light pollution and its harmful effects, has released new, free templates designed to guide local and regional governments in establishing outdoor lighting policies. Unlike the Model Lighting Ordinance (MLO), which was co-developed by DarkSky and the Illuminating Engineering Society (IES) in 2011 and spans 44 pages, the new DarkSky templates are streamlined to just 13 pages. This condensed format emphasizes ease of adoption, focusing on core principles for effective light management. Available for download on DarkSky’s website, the templates aim to help municipalities reduce light pollution, improve public safety, and lower energy costs.
The global rise in light pollution is primarily attributed to increased lighting in urban and suburban areas, as well as expansion into previously dark regions. With widespread adoption of cost-effective LED lighting, unintended consequences—such as increased brightness and expanded light pollution—have impacted both wildlife and human health. According to DarkSky’s Chief Program Officer, Brian Liebel, the templates provide municipalities with “a framework with simple objectives that capitalize on the positive attributes of LED lighting, such as improved optical design, dimmability, and warmer color temperatures.”
Five Principles of Responsible Outdoor Lighting
The new templates, grounded in the Five Principles of Responsible Outdoor Lighting developed by DarkSky and IES in 2020, encourage municipalities to focus on five key objectives for outdoor lighting:
- Lighting Only When Necessary: Lighting should be installed only where and when it is needed, with an emphasis on minimizing light usage.
- Targeted Light Distribution: Lighting should be directed solely to the areas requiring illumination to avoid unnecessary spill and glare.
- Appropriate Light Levels: Lighting intensity should be controlled to meet the specific needs of each environment without over-illuminating.
- Use of Controls for Efficiency: The templates recommend the use of dimming controls and timers to reduce lighting when not required, especially in the late evening or overnight hours.
- Warmer Color Temperatures: Lights should have warmer color temperatures to minimize disruption to ecosystems and reduce glare.
These principles, according to DarkSky, provide a straightforward way for municipalities to mitigate light pollution effectively while benefiting from current lighting technology.
Key Differences from MLO
The DarkSky Municipal Ordinance Template diverges from the more technically detailed Model Lighting Ordinance (MLO) in several fundamental ways:
- BUG Rating System: The MLO incorporates the Backlight, Uplight, and Glare (BUG) rating system, which assesses fixtures on their ability to limit these factors. It provides specific tables and requirements to ensure that light pollution is minimized through fixture choice. The DarkSky template, however, omits this system for a simpler structure.
- Dual Compliance Methods: The MLO offers two compliance pathways—Prescriptive and Performance—to accommodate varying lighting needs and budgets. DarkSky’s template, however, provides only a single, more generalized compliance approach based on the Five Principles.
- Hardscape Area Calculations: The MLO includes precise hardscape area calculations, offering lumen allowances based on the square footage of paved or developed areas. The DarkSky templates forgo these detailed calculations, opting for a broader application of light level controls.
- Detailed Street Lighting Requirements: The MLO covers a range of street lighting requirements, including standards for ornamental and functional street lighting. DarkSky’s templates address street lighting in a more general sense, aligning with the Five Principles rather than prescribing specific design parameters.
While the MLO’s technical depth and specific methodologies provide comprehensive options for light pollution control, DarkSky’s templates focus on a more straightforward, practical approach to assist governments in creating enforceable and effective policies.
Key Aspects of the DarkSky Template
The DarkSky Municipal Ordinance Template covers several core areas, each designed to address various aspects of outdoor lighting:
- Pre-existing Installed Light Fixtures: Guidelines for managing older lighting installations are provided, including approaches for upgrades and phased replacements.
- Exempt Applications: Lists applications that may be exempt from strict compliance, allowing for flexibility in specific contexts.
- Light Level: Defines appropriate light intensity levels to balance visibility with minimal environmental impact.
- Distribution: Specifies requirements to ensure light is directed only where it’s needed, reducing wasteful spill and glare.
- Trespass: Establishes measures to limit light trespass onto neighboring properties.
- Curfew: Recommends curfews and reduced lighting after specific hours to decrease nighttime light pollution.
- Controls: Encourages use of motion sensors, timers, and dimmers to optimize lighting use.
- Spectrum: Advocates for warmer spectrum lighting to reduce ecological disruption and glare.
- Maximum Lumens per Application: Sets maximum lumen allowances for specific applications to control light intensity and minimize pollution.
Specialized Templates
In addition to its municipal ordinance templates, DarkSky offers several supplemental resources to address specific lighting scenarios. The Illuminated Signage Supplement provides guidelines for managing light pollution from signage, ensuring visibility without excessive brightness. The Seasonal Lighting Supplement offers advice for holiday or event lighting, balancing festivity with responsible lighting practices. Additionally, the Coastal Marine Turtle Supplement targets areas near turtle habitats, outlining lighting measures to minimize disruption during critical nesting periods.
For broader legislative impact, DarkSky has developed a State Legislation Template and User Guide, tailored for states, provinces, or territories aiming to adopt outdoor lighting statutes. This template includes general but effective provisions to reduce light pollution and energy costs on larger state-owned properties without imposing mandates on local communities. To assist with legislative outreach, DarkSky also provides a Legislative Introduction Letter designed as a concise, compelling introduction to the importance of responsible outdoor lighting, intended to engage lawmakers and highlight the environmental and health benefits of reducing light pollution.
Accessing and Implementing DarkSky Templates
DarkSky’s templates are available for free on its website. These resources provide a customizable starting point for municipalities to craft outdoor lighting codes tailored to their specific needs. In addition to the main ordinance templates, DarkSky offers supplements for specialized lighting situations, including illuminated signage, seasonal lighting, and coastal lighting—particularly important for areas with marine turtle populations.
Governments adopting these templates can submit their drafted policies to DarkSky International for review. Upon adoption, the community may receive official DarkSky Recognition, joining a global network of cities, counties, and regions dedicated to preserving the night sky and mitigating light pollution.
